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LABORATORY ASSESSMENT IN THE CHEMISTRY CLASSROOM
By

Thomas Paul Hunt

A THESIS
Submitted to
Michigan State University
in partial fulﬁllment of the requirements
for the degree of

MASTER OF SCIENCE

Division of Science and Mathematics Education

1 998

ABSTRACT

LABORATORY ASSESSMENT
IN THE CHEMISTRY CLASSROOM

By

Thomas Paul Hunt

The objective of this thesis is to propose a comprehensive strategy for
Laboratory Assessment in the Chemistry Classroom that effectively evaluates
and validates the learning that occurs during laboratory activities. This thesis
provides the rationale and methods to implement a cohesive evaluation
procedure incorporating ten different forms of laboratory assessment. This
Laboratory Assessment procedme was tested on 92 chemistry students of
differing abilities. The students and teacher found this comprehensive approach

to laboratory assessment highly effective and enjoyable.

TABLE OF CONTENTS

List of Tables ................................................................................................... iv
List of Figures .................................................................................................. v
Introduction
Statement of Problem and Rationale for Study ......................................... 1
Comparison of old with new approach .................................................. 2
Where Laboratory Assessment ﬁts into the curriculum ......................... 3

Literature Review

Rationale for lab experiences in High School Chemistry courses ......... 5
Exploring the need for assessment during labs ..................................... 7
Laboratory assessment strategies ........................................................ 9
The use of lab based assessments to augment traditional tests ........... 19
Demographics of classroom ....................................................................... 21
Laboratory Assessment Implementation
Administration of pretest, surveys and interviews ....................................... 24
Implementation of assessment tools during lab activities ........................... 25
Implementation of post lab assessments into unit tests .............................. 34
Development of lab practicals .................................................................... 41
Administration of posttests, surveys, and student interviews ...................... 44
Evaluation
Pretest, Surveys, and Student Interviews ................................................... 46
Posttest, Surveys and Student Interviews .................................................. 53
Assessment Strategy Evaluations .............................................................. 59

Discussion and Conclusions

Laboratory Assessment Strategies Used During Laboratory Activities ....... 65
Laboratory Assessment Strategies Used After Laboratory Activities .......... 70
Summary .................................................................................................... 75
Appendices
A' Pretest and Survey ................................................................................. 78
8: Laboratory Reports ......... - ....................................................................... 8 1
C: Alkaline Earth Metal Lab ........................................................................ 86
D: Lab Assessment Strategies Used During Labs ...................................... 96
E: Lab Assessment Strategies Used After Labs ......................................... 103
F: Written Exams and Lab Practicals .......................................................... 116
G: Posttest, Strategy Evaluation, and Survey ............................................. 143
H: Open Ended Labs with Rubrics .............................................................. 150
I: Various Lab Assessment Activities ........................................................ 158
Bibliography .................................................................................................... 209

LIST OF TABLES

Table 1 — Pretest Results ................................................................................. 47
Table 2 - Posttest Results ............................................................................... 54
Table 3 — Laboratory Assessment Strategy Evaluation ................................... 60
Table 4 - Bug Juice Data Table ....................................................................... 85
Table 5 — Data Table for the Alkaline Earth Metal Lab ..................................... 94
Table 6 - Data Table for the Copper Formula Lab .......................................... 98
Table 7 — Calculations Table for the Copper Formula Lab ............................... 98
Table 8 - Performance Checklist for the Copper Formula Lab ........................ 100
Tale 9 - Peer Assessment Sheet for the Copper Formula Lab ...................... 102
Table 10 — Data Table for the Copper Formula Teacher Demonstration ......... 110
Table 11 - Chemical Bonding Investigation Sample Data Table ..................... 153
Table 12 - Data Table for the Observing a Chemical Reaction Task .............. 161
Table 13 - Supersaturation Data Table ........................................................... 185
Table 14 - Supersaturation Description Table ................................................. 186
Table 15 - Hydrates Lab Data Table ............................................................... 188
Table 16 - Logic Problem Data ........................................................................ 196
Table 1 7 - Sample Logic Problem Data .......................................................... 198
Table 18 - pH Ranges of Common Indicators ................................................. 202

LIST OF FIGURES

Figure 1 - Average Pre & Posttest Responses ................................................ 55
Figure 2 - Laboratory Report Format ............................................................... 81
Figure 3 - Acid I Base Performance Task ....................................................... 105
Figure 4 - Practical Exam Periodic Table Gn'd ................................................ 136
Figure 5 - Supersaturation Solubility Chart ..................................................... 186

Introduction

Statement of problem and rationale for study

There is an emphasis placed on book oriented Ieaming in today’s high
school chemistry courses. Due to demands on teaching time made by
curriculum, mandated testing, and administration, chemistry programs spend less
time in the laboratory and more time on “chalk and talk”. Teachers downplay the
importance of labs because of textbook constraints, safety concerns, and
indeﬁnite assessment results. This is disturbing.

There is a strong intrinsic value in the laboratory experience. Real
learning, the true understanding, of scientiﬁc concepts comes through everyday
world experience. Labs offer students those connections that can transform
theory into practice, and ideas into practical applications.

A belief in the importance of laboratory work is not enough. Teachers and
students lack the luxury of time to engage in “feel good" activities. To justify the
time and expense of labs, the Ieaming that goes on in the laboratory must be
assessed and validated. The objective of this thesis is to propose and analyze a

series of strategies for laboratory assessment in the chemistry classroom.

Comparison of old with new approach

Many chemistry teachers use lab manuals to manage the paperwork
associated with lab activities, since they provide tested procedures and data
sheets for each exercise. The regular use of these lab manuals is assumed to
provide the students with a quality lab experience that is easy to assess by the
teacher. The attraction these manuals have is quite signiﬁcant for both the
student and the teacher — perhaps because they do not require higher level
thinking of either. The student only needs to ﬁll in the blanks, and the teacher can
quickly grade them by simply surveying the data sheet for completeness.

The skills acquired and emphasized in lab activities must be more
substantive than the ability to follow directions and ﬁll in the blanks. The Ieaming
that occurs in the lab must be assessed and documented more accurately. Many
current lab manuals do not emphasize problem solving and critical thinking skills.
However, with modiﬁcation, common lab activities can be redesigned to
encourage higher level thinking and provide richer assessment opportunities. By
moonsidering the purpose of laboratory activities in the chemistry classroom and
how they we assessed, teachers can better measure and reward the Ieaming
that goes on in the laboratory. Through the systematic use of a formalized lab
based assessment process, students and teachers can gain a greater insight into
the value of laboratory exercises.

The lab based assessment process considered here differs from the

traditional approach to chemistry labs and their assessments in that it:

o Encourages the use of open ended laboratory exercises, requiring higher
level thinking skills, in place of the more common ﬁll-in-the-blank
“cookbook” lab exercises.

o Proposes that every test should contain some manner of hands-on
performance assessment designed to evaluate and reinforce laboratory
investigations.

. Proposes a process designed to make the chemistry class and its labs a
more cohesive undertaking rather than a collection of disjointed activities

that have no connection with what is covered in lectures or on tests.

Where Laboratory Assessment ﬁts into the curriculum

The laboratory based assessment program described in this thesis is
designed to be integrated throughout an entire chemistry course. During the
ordinary operation of a class, information about students’ understanding of
science is needed almost continuously. Assessment tasks are not afterthoughts
to instructional planning but are built into the design of the teaching. Through a
systemic implementation of a variety of assessment activities teachers can gain a
greater awareness of the students’ understanding of chemistry concepts and
their ability to actually perform scientiﬁc investigations.

Only by continuously evaluating students can a teacher gain a true
impression of the strengths of their students and the effectiveness of their
program. If assessment is relegated to a few disconnected “test days" then it

becomes an arbitrary intrusion into the ﬂow of the class that is designed to do

little more than put scores in the teachers grade book. These scores are false
indicators of the students’ learning since they may not truly measure what the
students understand. Erratic and inconsistent assessment destroys the
cohesiveness of the course and conveys a negative impression of the teacher’s
plan.

This thesis strongly advocates the use of laboratory exercises and
legitimate assessment of the Ieaming that occurs during these exercises. This
paper will analyze many different forms of laboratory assessment in terms of their
efﬁcacy and ease of implementation for both students and the teacher.
Legitimate laboratory based assessment is most effective when it is used
consistently and constantly throughout an entire chemistry course. It enforces an
air of relevance and accountability for the students’ Ieaming as it ties the
disconnected parts of a chemistry class into an integrated whole. Effective
laboratory assessment should be a constant, ﬁxed part of a successful course
since it promotes the reality of chemistry as an underlying fabric of our lives

rather than as a subject composed of isolated facts.

Literature Review

Rationale for lab experiences in High School Chemistry courses

Chemistry is an experimental science and without labs it’s not chemistry at
all. (Beach and Stone, 1988) It is clear than an understanding of the principles
and practice of science is an essential goal for all students. (Michigan State
Board of Education, 1991) Since science itself is an active investigation of the
world, students must physically explore the concepts and ideas presented in a
science course. Through lab work, students can appreciate the connectivity and
the complexity of science in the everyday world in a way that goes far beyond
book or rote knowledge.

“Laboratory experiments are the most effective method for Ieaming
chemistry." (Beach and Stone, 1988) Laboratory investigations can provide
practical examples of scientiﬁc ideas. These activities can provide the
“indisputable evidence and ample personal experience” needed for students to
reconstruct correct understandings of their world. (Miller, et. al., 1997) Labs allow
students to prove to themselves the truth of science and present students with
tasks that are interesting, worthwhile, and relevant to their lives. They can
validate the concepts covered in non-lab activities thereby making the entire
course more cohesive.

Lab activities deepen students understanding of subject matter through
multi-sensory experiences. During a lab activity, a student’s hands, mind, eyes
and other senses are focused on the task at hand, thus enhancing opportunities

for cognitive and personal growth. (Institute for Chemical Education, p.1, 1990)

Many sources agree that “hands-on/minds-on” science education is of a much
greater value to students than Ieaming from a book or lecture format. The
National Standards support this view of science as an “active process” with its
implied physical and mental activity. They state that “Learning science is
something students do, not something that is done to them.” (National Science
Education Standards, 1996)

The wide range of possible student Ieaming associated with well-designed
lab activities can be mapped in terms of Bloom’s categories. (Institute for
Chemical Education, p.2, 1990; Bloom, 1971) Psychomotor outcomes favorably
impacted by labs include manipulative, “hands-onlminds-on” skills such as
reading a meniscus, and adjusting a burner; as well as less obvious psychomotor
skills such as maintaining a readable lab notebook and taking effective action
when common lab hazards are encountered. Affective outcomes include the
development of positive attitudes towards lab-based instruction and the
cultivation of scientiﬁc attitudes. Cognitive outcomes such as knowledge,
comprehension, application, analysis, synthesis, and evaluation of chemical
concepts are all emanwd by lab activities.

Laboratory experiences teach safety applicable to the home and
workplace. They see proactive safety procedures that maintain a level of safety
in excess of the requirements found in most places outside of schools.

Labs can contribute to a student’s self-conﬁdence, decision-making
capabilities, and the ability to work as a team. Labs encourage students to

become users and controllers of information as they explore their world.

Exploring the need for assessment during labs

If the expense and logistics of labs are to be justiﬁed, the beneﬁts must be
more substantive than simple enjoyment, teachers must verify what the students
are Ieaming in the lab. We must develop ways to document the Ieaming in a
realistic, authentic manner that actually evaluates the Ieaming that we expect. It’s
a common-sense case that says if we value it, we should assess it...lf we don’t
assess it, we won’t get it (Wiggins, May, 1989)

An acronym coined to emphasize this point is called the WYTIWYG
Principle. It means What You Test Is What You Get. In other words, students will
strive to master concepts and skills that they believe you will assess. Many
teachers commonly believe that “If it’s worth Ieaming, it’s worth assessing”.
Students can reverse this logic to produce the observation that “If the teacher
doesn’t think it's worth assessing than it certainly isn’t worth Ieaming”!

”The WYTIWYG principle (What You Test Is What You Get) is as
trustworthy as Newton’s 3ml law of motion. The implications are obvious: We must
make our tests authentic embodiments of our goals; they must represent the
kinds of student work we value.’ (Carlson, 1991) If tests determine what teachers
actually teach and what students will study for - and they do - then the road to
reform is a straight but steep one: test those capacities and habits we think are
essential, and test them in context. (\Mggins, April 1989)

A portion of each student’s grade should be inﬂuenced by reliable lab
based performance scores. Since we need to measure and reward the Ieaming

that occurs in the laboratory in an authentic manner we must do more than

simply require a completed data sheet at the end of the lab. The students must
be inherently aware that what they learn in the lab is going to be on the chapter
test and is designed to make a bridge to the lecture Ieaming as well! We must
hold the students accountable for the Ieaming incorporated in the lab and require
that they demonstrate their understanding in multiple contexts.

We must design and implement multiple assessment strategies that
measure the Ieaming that occurs during the lab in both written and performance
formats. To those educators who worry that this sounds like teaching to the test -
it should! Teachers should “teach to the test” — a test that serves our educational
goals. At the heart of the science education improvement effort is the promotion
of instruction and assessment as an indistinguishable entity. (Lang, 1995) Lab
assessments should reﬂect everyday-life, interdisciplinary challenges in a
manner that is worth practicing and repeating. “Assessing science through
multiple-choice testing is like assessing Larry Bird’s basketball skills by asking
him to respond to a set of multiple-choice questions.” (Hein, 1991)

We, the educators, must provide opportunities for our students to
demonstrate their mastery of chemistry in a laboratory format. We are obligated
to give the students authentic tasks that rely on their knowledge of chemistry egg
their laboratory skills. By implementing a process of laboratory assessment, the
students’ content knowledge becomes a means to an end, not the end itself. In
this manner we can connect chemical concepts to our students’ lives and
reinforce in them the reality of chemistry as a ubiquitous experimental science

rather than just a confusing collection of isolated facts.

Laboratory assessment strategies

There is no question that we should develop rich assessment activities
that accurately evaluate our students in the lab. Textbooks almost universally
supply lab books that suggest lab activities, complete with worksheets designed
to guide and evaluate students. In their attempt to provide a very marketable lab
book that will be successful for students and easy to use by teachers, they often
produce lab guides that are little more than “cookbooks". These lab guides give
too much direction and too little room for exploration and higher level thinking.
They fool the teacher into believing that they offer strong lab experiences that
allow the teacher to evaluate their students’ understanding of important chemical
concepts. Instead, they may merely result in students who are very good at
following step-by-step directions and ﬁlling in blanks. These students are
deprived of the opportunity to design their own procedures in open assessment
activities and the teacher is left to evaluate the students based on only very
minimal data about low level thinking skills.

Desiming alternate assessment strategies is the challenge. Good
assessment tasks should be natural parts of the curriculum that are feasible,
inviting, and capable of meeting the scoring and reporting needs of everyone
involved. Successful assessment strategies must be both effective and efﬁcient
in their use of time and materials. They must stimulate all levels of thinking and
multiple cognitive domains.

Fortunately, the Ieaming environment is replete with opportunities to

evaluate our students, particularly during laboratory exercises. We can assess

 

students in a variety of ways: we can observe what they do, listen to what they

say, read what they write, and analyze what they produce. Any behavior that can

be observed can be adapted for assessment. (Hein, 1991)

The following is a description of alternative assessment strategies that can

be used during the lab to give teachers a better understanding of what the

students really know:

Laboratory Notebooks - Instead of using pages from the typical ﬁll-in-the-
blank lab books provided by textbook manufacturers, a teacher may
require their students to maintain a laboratory notebook, where the
student is required to keep a neat and organized log of all the lab
activities. The students are responsible for recording all the different steps
of the investigations including, for example, Purpose, Procedures, Data &
Observations, Calculations, Results, Conclusions and Reﬂections. In this
way the students can learn through example how to begin thinking about
how to create a carefully designed experiment while Ieaming the
intricacies and advantages of efﬁciently designed lab notebooks. Only by
actual practice can students learn to write the “clear, step-by-step
instructions for conducting investigations” advocated by the Benchmarks
for Scientiﬁc Literacy: Project 2061. (1993) By requiring the use of lab
notebooks the teacher encourages individual thinking and higher level
learning. The teacher also acquires a yearlong assessment tool that can
record growth over time - something that can not be easily evaluated by

standard rip-out and hand-in data sheets from a lab book.

10

 

Performance Checklists — These are lists of traits or Ieaming behaviors
that the teacher wishes to focus on and record when evidenced by the
student. They encourage speciﬁc, systematic evaluation in an easy-to-use
format. They can provide a clear picture of student progress over time if
used regularly throughout the school year. The teacher creates a
performance checklist by identifying and listing important target behaviors
that they wish to observe and evaluate. The teacher’s behavior is a visual
cue that the lab activities the students are involved in are important and
the students will be held accountable for their actions during the lab.
Frequent, obvious use will reduce the students’ concern about the
evaluation.

It the teacher wishes to have reliable data, periodic use of
performance checklists is necessary, Since a single instance does not a
pattern make. Students who have truly internalized appropriate lab
procedures will demonstrate them consistently — not sporadically.
Interview Sheets -— These are lists of questions used by the teacher to
moord and evaluate student impressions and insights. They are
traditionally used in a conference format either before or after a unit.
Interview sheets are equally proﬁcient at ascertaining a student's prior
knowledge or exit knowledge. They have the added beneﬁt of encouraging
direct communication between the student and teacher about their
feelings concerning the student’s progress, the lesson, and the teaching

associated with a unit. The teacher uses an interview sheet to focus their

11

questioning and to Simplify the recording as they discuss with the student
their understanding of the lab. A carefully designed interview sheet can
target important behaviors and keep the documentation manageable.
Effective interview sheets should encourage thorough and efficient
assessment.

Peer Assessments - Informal peer assessment is a constant part of every
classroom. A teacher can formalize this process by following up a lab
activity with a written evaluation assignment that encourages the students
to reﬂect on their partner’s and their own performance in the lab. Students
present a work-in-progress while others critique and offer feedback on
their impressions of the student’s work. Peer assessment can also be
used to evaluate teamwork skills and individual contributions. It is a useful
technique for fostering cooperation and mature work habits; and
encouraging all students to be individually accountable for their work
during a lab. Students can acquire the ability to self-evaluate as they
evaluate others and are judged by their peers in retum. I believe that this
process identiﬁes student strengths and weaknesses as a team member
and teaches the students toleratce of the different roles students play in
group dynamics.

Performance Tasks - These performance assessments require the
student to actually prove that they understand the material as they
demonstrate to the teacher speciﬁc scientiﬁc procedures. Unlike traditional

tests that focus on facts and discrete skills, performance assessments are

12

designed to test what we care about most - the ability of students to use
their knowledge and skills in a variety of realistic situations and contexts.
An example would be to require the students to experimentally determine
the percent of water in a hydrate rather than just do a percent composition
math problem on a test. Performance assessments are motivating since
the students get to do “real” chemistry rather than just talk about it.
Performance assessments can connect the classroom and the everyday
world by having students demonstrate the chemistry of common products.
Demonstration books offer a large amount of readily available
background material for activities that can be modiﬁed into performance
tasks. Because of the abundant amount of background, explanations, and
descriptions provided to teachers, it is very easy to determine the
appropriateness of a demonstration for a performance task. These same
materials give extensive information on the materials and solutions
required for the demonstrations as well as important safety guidelines.
Open-Ended Laboratory Exercises — This is a form of embedded
assessment designed to encourage higher level thinking. These activities
provide a minimum of directions from the teacher and an opportunity for
the students to design their own approach to the required task. They offer
a rich assessment opportunity for the teacher to evaluate the content
knowledge, performance abilities, laboratory skills, and conceptual

understandings of the student.

13

Most chemistry teachers have a large collection of laboratory
books. Though they are overly structured and inﬂexible, they do provide
exercises with the rigid framework and support some students need when
they encounter new material. As written, they offer excellent initial Ieaming
opportunities, but they do not truly assess the Ieaming that occurs. By
pairing up a set of Similar labs we can eliminate this shortcoming. A
second, similar lab is modiﬁed to be more open-ended and investigative in
nature, making it a superior assessment activity that more accurately
evaluates the Ieaming the occurred during the ﬁrst lab. In this way we can
assess and conﬁrm the learning that occurred in the ﬁrst lab and reinforce
its value as we hold the students accountable for the Ieaming in the
second lab.

The ﬁrst step in creating this type of assessment exercise is to
identify the speciﬁc Ieaming objectives to evaluate. The teacher must
carefully review the previous practical experiences the students have had
related to the objectives. The task must be stimulating, but not
overwhelming, and allows the students to successfully apply previously
learned skills and knowledge.

Open-ended labs are actually quite easy to devise once the teacher
learns to “let go” a little bit. ln open-ended labs the teacher takes on the
role of facilitator and relinquishes the role of teacher to the students. This
is not an easy paradigm shift and it is easy to get baited out of it by

students who emotionally plead for speciﬁc procedures when all they

14

really need is a hint to nudge them back on to the right track Teachers
who start with a clear view of their intended outcomes in open-ended labs
ﬁnd the process easier for their students to perform and easier for
themselves to assess.

Teacher Demonstrations - The students are required to analyze and
explain a chemical reaction performed by the teacher. This form of
laboratory assessment is quick to perform, easy to modify, and informative
in its evaluation of the students’ abilities. It allows the teacher to use
highly-motivating “exocharmic demonstrations” that convey the unspoken
message that science is exciting. (Shakhashiri, 1983) Teacher
demonstrations can maintain the authenticity of a testing assignment while
at the same time allowing for multiple modalities of Ieaming. The students
actually “see” the reaction they are being asked about rather than having
to just picture it in their mind in response to a written question. Teacher
demonstrations can be easily modiﬁed into Lab Based Assessments
suitable for inclusion in unit tests. Since chemical demonstrations are used
as a teaching strategy it is natural and even advantageous to also use
them to assess the student’s comprehension of the material. This
approach validates the purpose for doing the demonstrations and holds
the students accountable for the ideas presented by demonstrations. In
this manner we can engage the students brains as we entertain them with
the “magic” of science. Demonstrations should do much more than

impress the students - they should actually teach and assess as well.

15

 

 

Teacher demonstrations are modiﬁed into Laboratory Based
Assessments (LBAs) based on the ideas and skills the teacher wishes to
assess. Some skills or ideas that a teacher desires to assess may have
only a limited number of activities that can be used to assess them. Often
some of those activities that could be particularly effective are not suitable
for the students to work with directly. This may be due to the expense of
materials such as in activities that use a signiﬁcant amount of silver
nitrate. Another reason for not having the students perform the activities
directly might be because of serious safety hazards inherent to the activity
- such as in an activity that would require the students to handle
concentrated sulfuric acid.

Another advantage to using teacher demonstrations to assess the
Ieaming that occurs during lab activities is the efﬁciency with which a large
number of students can be evaluated. Teacher demonstrations are very
economical in terms of class time and materials. They also guarantee that
everyone gets the same initial information. This helps verify that we are
truly assessing the students’ ability to interpret the data - not collect it.
This can remove the procedural stumbling blocks sometimes present in
labs that might mask a student’s ability to perform some calculation,
interpret data, or analyze results. Since students complete their part of a
teacher demonstration independently, it also promotes individual

accountability since students can not rely on others to “carry them”.

16

 

0 Lab Oriented Written Tests - These are speciﬁcally designed to evaluate
the learning that occurs in the lab, and to encourage higher level thinking,
through the use of a variety of higher-level questioning techniques
including enhanced multiple-choice questions. Enhanced multiple-choice
questions are designed to be more challenging in terms of the thinking
required to determine the correct response. They are designed to be
reﬂective of experimental data and situations that require the student to
identify relevant information and manage the appropriate variables
accurately. They can also be made more open-ended by requiring
students to defend the choice they make. The appropriate use of
scaffolding (information provided in the task itself to help students frame
their responses) can improve the quality of responses as it fosters
students’ best thinking and writing.

Written assessments are quick, effective ways to check for
understanding. They require no additional materials and pose no safety
concerns. They force every single student to be individually accountable
for the Ieaming and can be very speciﬁc in the information they test.

. Conceptualization Activities — These are used to evaluate student’s
understanding of the theories and concepts required to explain the
observations encountered during a lab or demonstration. The main
difference between these activities and other forms of assessments is the
type and depth of the questions posed by the teacher. In these activities

the students’ ability to collect and manipulate data is less important than

17

their ability to rationalize how the data supports overriding theories and

principles. Whereas most LBAS often test for important basic information

and terminology, conceptualization assessments are generally looking for
more theoretical explanations such as why certain reactions occur. Unlike
other assessment tools in which the student’s ability to carefully observe

the demonstration is critical, conceptualization activities often use a

demonstration only as a prompt to aid student thinking. The physical

demonstration offers a bridge from the concrete laboratory activity to more
theoretical or abstract concepts.

0 Laboratory Practicals - These require the students to demonstrate their
knowledge and skill by performing a series of performance tasks in the
laboratory. This form of assessment allows the teacher to evaluate
numerous student attributes including the ability to follow directions,
manipulate equipment, perform labs, analyze data, and perform open-
ended investigations.

All of these tools are excellent alternatives to the “cookbook" evaluations
offered in traditional lab books. When all, or many, of these assessments are
used regtﬂarly, they can transform the evaluation process into a richer, livelier
process that is rewarding for teachers and learners. “I used to teach children and
evaluate their progress. But now I kid watch, facilitate the Ieaming of children and

try to discover why learners do what they do.” (Mitchell, 1992)

18

 

The use of lab based assessments to augment traditional tests

Traditional tests, in spite of their efﬁciency and economy, often fail to tell

us what we want to know the most. (Hart, 1994) Traditional multiple-choice tests

hinder teaching and Ieaming by

Putting too much value on recall and rote Ieaming at the expense of
understanding and reflection.

Promoting the misleading impression that there is a single right answer for
most every problem.

Turning students into passive learners who need only to recognize, not to
construct, answers and solutions.

Forcing teachers to focus more on what can be tested easily than on what
is important for students to Ieam.

Trivializing content and skill development by reducing whatever is taught
to a ﬁll-in-the-bubble format.

Traditional testing has created a lingering false assumption about the

purpose of assessment, implying that assessment should bring closure to

Ieaming. (Michigan Assessment Team Assessment Guidebook, 1995) This is in

direct contrast to the goals of embedded assessment that suggest that

assessment Should be integrated so that it is an ongoing process rather than a

culminating activity. The best time for assessing what children know and can do

is during instruction while the students are actively involved in the Ieaming

process, constructing their own knowledge and ﬁnding their own solutions, and

19

not after instruction, when students passively ﬁll in bubbles showing that they
understand the test designer’s solutions. (Annenberg, 1998)

Traditional tests have been used to evaluate students because of their
efﬁciency for a long time, and will continue to be a primary form of assessment in
spite of their limitations. Students need to be able to successfully demonstrate
their understanding of chemistry on important standardized tests such as the
High School Proﬁciency Test and Advanced Placement Chemistry Exam. They
need to acquire both the knowledge of chemistry and the test-taking skills
necessary to pass these tests. A teacher must remain aware of the reality of this
situation and prepare their students for it. It is in the best interest of the students
to teach them in a manner that encourages successful Ieaming and assessment
both in the present course and on these external measures of success.

Consequently, teachers must not abandon traditional testing formats
altogether. The problem is the overuse of traditional testing to assess our
students. This approach turns students into passive learners. It forces teachers
to focus only on what can be easily tested and fragments the course into a
disjointed collection of lectures, labs, and tests.

Ou' students will reap the greatest beneﬁt if we assess them regularly
using a combination of both formats during each unit of instruction. Combining
written tests with laboratory based performance assessments allows the teacher
to maximize the Ieaming and assessment opportunities available in both formats

while preparing them for the SAT, future courses, and the world at large.

20

 

4

Demographics of classroom

Jackson High School is a large Class A high school with 1648 students
enrolled in the ninth through twelfth grades. The school district is the largest in
Jackson County with a total enrollment of 7,456 students. It is an urban school
district with a diverse student population including a large number of families
from the economically depressed “inner—city" areas within Jackson. 32% of our
students are minorities and 45% of our student body is ﬁnancially disadvantaged
and qualify for free or reduced lunch programs.

With the advent of today’s schools-of—choice we are seeing our student
population change since parents have increased freedom to choose whether
their children attend our school. This is contributing to our student population
becoming more polarized. One group is very school- and career-oriented with
strong parental support, and the other group is academically challenged and
unmotivated with poor family backgrounds.

The schools-of-choice option has allowed us to successfully recruit over
one hundred new students into our high school, since we are generally perceived
as having the strongest academic curriculum in the county. For example, the size
of our program allows us to offer fourteen different science courses as compared
to the average of six science courses offered by other local school districts. The
quality of the high school’s science, music, and foreign language departments is
speciﬁcally cited as the main reason many of our new students have transferred
to Jackson High School. The typical students attracted to our school by our

curriculum are highly motivated and academically successful.

21

On the other hand, we are also losing students to surrounding school
districts at an alarming rate due to perceptions of racial tension and a lack of
discipline at our school. These reasons have been speciﬁcally cited by the
families of some of the more than three hundred students that have left our
school district at the elementary and middle school levels. As afﬂuent families
continue to move out of Jackson Public School District to the large number of
wealthy housing developments in neighboring school districts, we see well-to-do
but not particularly academically-oriented students leaving our school. These
factors result in a polarization into groups composed of either the high-powered,
university-bound students or the economically deprived, at-risk students.

We offer three levels of chemistry at Jackson High School. Our Practical
Chemistry course is a “math—less” Chemcom course designed to provide very
basic chemical literacy and help meet the needs of student science credits
necessary for graduation. The students in our other two levels of chemistry
(General and Advanced Placement) have chosen to take these elective courses
even though they have already completed the number of science credits needed
for graduation. The General Chemistry class, on which this thesis is based, is a
math based college-bound chemistry course for both science and non-science
majors. Our Advanced Placement Chemistry course is offered only to seniors
and is a highly successful college-level chemistry course designed for students
wishing to pursue a career in the sciences.

In this study of Laboratory Assessment in the Chemistry Classroom, 92

students (36 male and 56 female) from three General Chemistry classes were

22

 

involved: 75 sophomores, 15 juniors, and 2 seniors. The average grade point of
the students included in these classes was a 2.98 and their average expectation
was to spend 1-2 hours a night on homework. The study group included 67 who
indicated an intent to take the Advanced Placement Chemistry as seniors and 69
indicating they plan to study science in college. Eighty four percent indicated that
they were part of a two-parent family. 15% were identiﬁed as being economically

disadvantaged and 22% identiﬁed themselves as belonging to a minority.

23

Laboratory Assessment Implementation
The systematic implementation of effective laboratory assessment caused
me to thoroughly reevaluate my entire approach to teaching chemistry. I found
very few areas that did not require signiﬁcant revision as I attempted to develop a
more cohesive assessment procedure that would be more informative. The
following is an outline of the steps I used in developing laboratory assessment in
the chemistry classroom:
1. Administration of pretest, survey, and student interviews
2. Implementation of lab notebook procedure
3. Implementation of other assessment options during labs
4. Revision of tests to incorporate lab based assessments, performance
tasks, and authentic assessments
5. Development of lab practicals

6. Posttests, surveys and student interviews

Administration of pretest, survey, and student interviews

All of the students involved in this study were given a pretest and survey
designed to identify student perceptions about the role of labs in science
courses. The pretest was a series of statements to which the students were to
indicate their degree of agreement using a numerical scale. The scale ranged
from a one (indicating strong disagreement) to a ten (indicating strong
agreement). The complete pretest can be found in Appendix A, part 1, and the

survey can be found in Appendix A, part 2.

24

 

Based on the answers students provided on these pretests a cross-section of
students was selected for in-depth interview about these ideas. Students with
high, average, and low performances in past science courses were selected. The
students were encouraged to discuss their impressions of the purpose and the

validity of labs and their assessment in science courses.

Implementation of assessment tools during lab activities

The use of a laboratory notebook was instituted to provide a more
authentic assessment of laboratory activities. Each student was required to keep
a complete account of all lab activities for the entire chemistry course.

For the sake of uniformity, the students were provided with a blank, spiral-
bound, college-ruled notebook. The color-coded name labels identiﬁed the class
the student was in and simpliﬁed the handling of the large number of notebooks.
To minimize the wear-and-tear and the number of lost notebooks, the students
were encouraged to keep their notebooks in the classroom when they weren’t
using them.

The students were told at the very beginning of the course that they would
be using lab notebooks throughout the entire year to raise their level of laboratory
reporting to what would be expected of them in college labs and in a
professional, working laboratory. The students were informed of my intent to
have them produce a lab write-up for every lab performed in this class. They
were given speciﬁc instructions on how to use and maintain their notebooks.

I explained to the students that they would usually be given a “pre-Iab"

paper the day before the lab that would have all the information they would need

25

 

to begin writing their lab reports into their notebooks. I wanted to ensure that they
had read and understood the procedures and safety precautions before they
began the lab the next day. These “pre—labs” varied from being very speciﬁc in
their procedures to being very open-ended, depending on the goals of the lab
and the students’ gradually improving record keeping abilities.

The students were encouraged to use the lab report format shown in
Appendix B, part 1 for all labs in this course. It is an adaptation of the one
suggested by the Michigan Department of Education in its Model Instructional
Unit. (Michigan Department of Education) The students were given these
instructions regarding the appropriate protocols for laboratory notebooks.
Appendix 8, part 3 lists some advantages gained by the use of these notebooks.

To help the students Ieam the process and purpose for using this lab report
form the class examined a selection of “pre-labs” and acceptable lab reports.
Appendix 8, part 4 contains one of these sample lab reports. We discussed how
“pre-labs”, with their background explanations, safety precautions, and lab
procedures, should be modiﬁed to conform to our standard report format. The
students were instructed on how to create their own data tables to record their
observations, data, and calculations. After examining the sample, the students
were assigned their ﬁrst lab report to record in their notebooks using this
laboratory report format. Before beginning the lab the next day, the lab and the
notebooks were discussed in detail.

Students require time to acquire the ability to write accurate, organized lab

reports. The students need to clearly understand the teacher’s expectations as to

26

what, when and where they should record pertinent information from the lab.
Early lab activities must allow for this learning period and frequent feedback from
the teacher prior, during, and after the lab will dramatically cut down on the time
necessary for the students to create professional reports. I required that the
students must have completed the Purpose and Procedure sections of the lab
report the nig'lt before the lab. For the ﬁrst few labs of the year, I also required
that they show me the data table they planned to use BEFORE they began the
lab. Many students initially required assistance in developing suitable data tables.
I chose to include a suggested data table in some of the early pre-labs. l
gradually phased these teacher-created tables out of the pre-labs as the
students’ abilities improved. The students were expected to record data and
observations as the lab progressed and to complete the entire lab report before
the next day.

For maximum benefits, the laboratory activities must be rewritten to be
“minds-on” as well as “hands-on” so that the major cognitive skill being cultivated
is something more than the ability to accurately follow written directions. The
decision to use lab notebooks is a major commitment for a teacher. This decision
will signiﬁcantly change the way in which a teacher prepares and evaluates a lab
experience. Lab reports encourage deeper Ieaming for the students and give the
teacher a much richer assessment of their understanding and abilities.

For an example of this transformation I modiﬁed a lab found in Prentice
Hall’s Laboratory Manual. (Wagner, 1989) The lab is Shown as it might be found

before (Appendix C, part 1) and after being transformed (Appendix C, part 2).

27

The major deﬁciency of the “typical” lab procedure is the general format of
the laboratory manual itself. The tendency of my past students was to skim
quickly through the procedure and rip out the data Sheet so they could hand it in
as quickly as possible. The students rarely read the background material since it
was just “ﬁller" in between what really counted - the data sheets. They felt that
they had completed the lab once they had ﬁlled in all the blanks on the data
sheet. Their goal was to ﬁll in the blanks, not learn the material.

The data sheets rarely contained graphs or tables to help organize or
interpret the students’ information. The students developed very little
appreciation for how to manipulate and present the data collected during a lab.
They were unaware of the amount of interpretation and analysis that occurs in
the lab following data collection. Consequently, the students performed very
poorly on later assessments that asked them to analyze the processes, data, or
reasons for performing these labs.

Some lab manual procedures have deﬁcient or missing sections on safety
and equipment. They sometimes make reference to equipment that is not
available. They often use materials that are no longer considered safe to use in
high school labs. These labs often fail to give sufﬁcient background for the lab.
When such information is given, it is often unsuitable and confusing to the
students.

Appendix C, parts 1 and 2 Show that rewriting a traditional lab into a
format suitable for use with the lab report outline can be a lengthy process. I

found that the students needed very speciﬁc directions about what to include in

28

which portion of the report. This required very careful rewriting of the directions
for each lab I planned to use. Coincidentally, it also made it very convenient to
modify the lab to my purposes since the students weren’t going to use the
original lab instructions anyway. I always gave some background about the lab
and why we were doing it.

The logistics of using laboratory notebooks requires some additional
planning for the teacher. Students must be given the appropriate pre-labs the day
before the intended lab day so that they will have sufﬁcient time to record the
procedures and create data tables prior to the lab. Sufﬁcient time must be
allotted for the students to complete and hand in their notebooks following lab
exercises.

Reading and grading the lab notebooks is a time-consuming process. It
was easiest to grade every student’s report for a speciﬁc lab activity all at one
sitting. This gave me a better impression of how the students compared to each
other and encouraged uniformity in grading. To prevent speciﬁc labs from having
an undue impact on the grading system, all labs were graded on a basis of ten
points. A perfect score of ten was recorded for lab reports that were complete
and accurate. Incomplete reports (those missing sections speciﬁcally required by
the standard laboratory report format) could only earn a maximum of ﬁve points.
Reports that were complete but inaccurate would earn a score usually between
ﬁve and ten points. I enjoyed writing comments on their labs that were intended

to improve their reporting skills and their understanding. I also used this feedback

29

to show them that I cared about what they wrote. I received many positive
reactions from students because of these responses.

Grouping students for lab activities is an important consideration. If we
want to hold students truly accountable for their Ieaming we must remove the
temptation and possibility of relying on their lab partner to carry them through the
lab. Lab notebooks can help ﬁght this temptation - it’s difﬁcult to copy an entire
lab report! Rotating lab partners will also reduce the tendency for one student to
always be the leader and another to always be a follower. If students can not rely
on having a “smart” lab partner they are forced to become more self-reliant. The
validity of lab based assessments is increased if students are required to perform
an assessment activity with a different partner than the one they had during the
la in which they were to Ieam the skill being evaluated. 1 developed a workable
strategy for the frequent rotation of lab partners that was viewed as being fair by
the students. First, I posted all the names of the students for my class in two
columns on the bulletin board. The students could see who their partner was for
that day‘s lab by looking to see whose name was next to theirs’ on the board.
After each Id) activity, one column was moved so that the students never had the
same lab partner twice in a marking period. In this way the students were held
accountable for their own ability to Ieam and function in the lab.

To maintain the continuity of the course and improve the validity and depth
of the evaluation it is beneﬁcial to vary the format of assessment items. Multiple
assessment activities will teach students more about the subject as they reveal

more about the students to the teacher. In addition to the lab notebooks, I also

30

used performance checklists, interviews, and peer asSessments to assess the
students in the lab. Each of these assessment tools has its advantages and
disadvantages. The assessment strategy being used should be tailored to the
Ieaming being evaluated.

An assessment task without a previous learning activity is a test of prior
knowledge - not of learning. Consequently, although most of these assessment
strategies could be modiﬁed to be initial Ieaming activities with built-in embedded
assessment, I usually used them as a secondary activity designed to evaluate
the students’ understandings of Ieaming objectives I had targeted in earlier lab
experiences. It was important to match the assessment to the desired lab
outcomes. These lab assessments were not, and should not, be limited to lower
level knowledge skills. However, assessment of higher order skills is not feasible
if the original lab activities were not designed to develop these skills. You can’t
test what the students haven’t practiced!

l varied the assessment strategies I used based on the skills and
additional learnings I wished to evaluate. For the sake of this study, I used all of
these assessment options to evaluate a single lab - one in which I hoped my
students had leamed to experimentally determine the empirical formula of a
compound. This lab was the Copper Formula Lab. The following paragraphs will
show how I used the four different forms of laboratory assessment that can be

used during a lab with this one lab experience.

31

The students were given a highly structured pre-lab, which they wrote up
as a lab report and then performed in lab. This pre-lab as shown in Appendix D,
part 1, is one form of lab assessment that could be used during this lab.

As the students performed the Copper Formula Lab, (the I used a
performance checklist (Appendix 0, part 2) to evaluate their performance. When
using performance checklists, I found it helpful to circulate among the students
during the lab activity and recorded as many observations as possible. I also
used performance checklists to provide important checkpoints during a lab to
help manage the ﬂow of the lab. These checkpoints required the students to
report their data to me and receive approval before proceeding. These required
data checks insured that the class was working at the same pace and reduced
the safety concerns inherent to some labs. These checkpoints were also used to
collect student data that was then reported to the entire class by displaying
various lab groups’ data on the board. This technique produced a large amount
of data in a timely manner that was useful for graphing or other statistical
manipulations.

Another form of assessment that was used during the Copper Formula
was the interview Sheet. With this tool, I asked the students about their
perceptions of the lab by asking questions such as “Why did this lab require two
days?“ The complete interview sheet can be found in Appendix D, part 3.

Since it is logistically difﬁcult to conduct an interview with every student
during a lab, I prefer to use a rotation to assess only a small number of students

using interview sheets during any particular lab. I select a small number of

32

students beforehand that represent a cross section of my class. I prefer to use
two academically successful students, two medium ability students, and two
students who are having academic difﬁculties in my class. The responses the
students offer can give a quick insight to what the labs look like through a
student’s eyes. By using a heterogeneous sample, I feel that I get a
representative indication of the clarity and success of the lesson. Student
responses highlight weaknesses in the lesson’s design, allowing me to make
corrections immediately to improve the Iab’s effectiveness for the rest of the
class. For example, if I ﬁnd that a large number of students are having the same
difﬁculty or are failing to understand why a particular step in the procedure is
necessary, I can correct this problem immediately.

The fourth form of evaluation that I used during the Copper Formula lab
was peer assessment. I used peer assessment sporadically, throughout the
course — usually in conjunction with some form of teacher moderated
assessment. The peer assessment form I used for the Copper Formula lab can
be found in Appendix D, part 4.

I felt that to have successful peer assessment I would need to ﬁrst provide
the students a chance to practice this strategy in a non-threatening manner. I
used the Claaping Hands performance assessment activity (Busik, 1995) to give
the student’s the opportunity to rehearse giving each other feedback. Through
the discussions generated by this activity I attempted to teach the students how
to assess others and what constitutes useful feedback. I felt that the students

were much less apprehensive about peer evaluations following this exercise.

33

Implementation of post lab assessments into unit tests

I wanted to continue to use traditional unit tests because of their inherent
advantages and the need to prepare students for standardized testing; yet, I
wanted to avoid being over reliant on this strategy. I wanted my students to be
constantly responsible for all of the material presented throughout my course and
be able to use the lab to physically demonstrate or explain what they have
learned in both labs and other non-lab activities. Therefore, I attempted to
incorporate a band’s-on, authentic, Lab Based Assessment (LBA) of each
student’s understanding into every test or quiz in my class. LBAS were designed
to be physical demonstrations (authentic assessments) of what the students
actually know.

The most common form of LBA I used were performance tasks that
required the students to carry out certain chemical procedures. These
performance tasks were quick and direct evaluations of particular abilities of the
students. They tended to be simple in design and minimal in terms of required
resources. These tasks were very concrete and speciﬁc in the knowledge they
assess, such as the ability to determine the density of an irregular solid. They
were presented as self-directed labs that ask students to design their own
experiments while at the same time reinforcing important laboratory skills such as
the ability to write formal laboratory reports.

The Density of Sand Assessment in Appendix E, part 1 is an example of

how assessment and reinforcement of skills can occur at the same time. I used

34

the exercise to assess the students’ ability to create an experimental design that
would solve a realistic density problem. I reinforced their reporting skills by
designing the task so that the students would create a suitable lab report as the
written product

The Density of Sand performance task quickly identiﬁes students that are
having difﬁculties with density. Its design encourages higher level thinking as the
students create their own experimental procedure. The formatted report
requirement provides enough structure to keep the students on the right track
and reinforces how lab reports should be written.

Performance tasks can also be designed to be very conceptual or
theoretical in nature. An interesting way to present this form of LBA is to design it
as a logic problem that the student can solve using receme learned material.
Appendix E, part 2 shows an example of how a logic problem can be used as a
performance task at the end of a unit, in this case, one on acids, bases, and
indicators. To successfully complete this LBA the students need the appropriate
chemical knowledge and sufﬁcient prior experience with solving lab-oriented logic
problems before beginning this unguided task.

I also used open-ended labs as LBAS. These tend to be longer and more
encompassing in nature than performance tasks. Whereas a performance task
might assess only one or two ideas, open-ended labs would require and
therefore evaluate the student’s ability to compile a whole host of ideas and

competencies.

35

At the end of the percent composition unit that included the Copper
Formula Lab, the students were given a traditional test to be completed
individually. They were then asked to determine the percent iron in an iron
chloride compound by using two strips of aluminum and an iron chloride salt.
This Lab Based Assessment was an open-ended lab intended to evaluate their
understanding of the appropriate chemical process and their ability to physically
design and demonstrate a correct laboratory procedure that would accomplish it.

To successfully complete this exercise each student pair was given the
same materials used in the Copper Formula lab. The lab activity required me to
substitute iron (Ill) chloride for the copper (ll) chloride used in the Copper
Formula lab. The procedure and safety items are the same. Since the iron (Ill)
chloride is a hexahydrate, the anticipated student result for the percentage of iron
is 55.8 I 270.3 x 100% = 20.6%

This type of performance task is an effective assessment of what was
learned in the ﬁrst experiment. It can be easily modiﬁed to elicit speciﬁc target
behaviors. If the teacher’s goal is to evaluate the students’ abilities to perform the
mchanical aspects of the lab and the associated computations, then the
students would be required to produce an experimentally derived value.
However, if the teacher wishes to assess the students’ abilities to produce a
step-by-step written procedure then the students could be required to submit a
formal lab report for the process they used during the exercise.

Wnen safety or expense constraints warranted, the LBAS were designed

as teacher demonstrations during traditional tests, which the students would be

36

required to explain. These demonstrations can be very simple and direct in what
information they require the students to have mastered. They can also be very
sophisticated requiring the students to coordinate many previously studied
concepts into a single suitable explanation of the demonstration.

The Lab Based Assessment in Appendix E, part 3 was a teacher
demonstration designed to evaluate the students’ ability to interpret and balance
chemical formulas and equations. Important safety and background information
as well as teacher instructions for this demonstration can also be found in
Appendix E, part 3. I performed this LBA as a series of reactions that converted
sand into magnesium silicide, then into silane, and ﬁnally back into sand again.
The students answered questions and balanced equations for each reaction in
the demonstration. This demonstration is based on a silane demonstration
presented by Paul Hunter and Sheldon Knoespel (1994) at a Michigan Science
Teachers Association convention. This particular demonstration was chosen to
be modiﬁed into a teacher demonstration assessment because of its multiple,
straightforward chemical reactions, its eloquent cyclic nature, and general class
appeal. Since this LBA was used early in the course when the idea of balancing
was fairiy new to the students, it is highly structured and offers hints for those
who need a slight nudge in the right direction.

A second form of teacher demonstration is shown in Appendix E, part 4.
This LBA was used to assess the Ieaming that occurred in the Copper Formula
Lab. It used an experiment very similar in design to the Copper Formula Lab. l

arranged several lab setups on the demonstration table depicting important steps

37

in the determination of the percent iron in an iron chloride compound using two
strips of aluminum and iron (Ill) chloride. Student volunteers determined the
relevant data and then posted this information for the class.

Occasionally the Laboratory Based Assessments were conducted as
written assessments or conceptualization activities. These approaches are
particularly suitable for highly conceptual ideas that would be difﬁcult or
impossible to actually perform in a high school chemistry laboratory. They also
reinforce strong scientiﬁc reading and writing abilities that can help students on
future standardized tests and eventually in the workplace. I usually included
these assessments on the next unit test. There are several advantages to doing
this. First — it makes the test more authentic and less intrusive. Second — it sends
a clear message that the labs and the learning that occurs in them is important
and will be evaluated. Third - it encourages the students to internalize and apply
the new Ieaming. The written assessment in Appendix E, part 5 was used
following the Copper Formula lab.

Item number one from this assessment was designed to recreate the lab
on paper. It determines whether the student could perform the calculations
required by the lab and understood all the necessary steps.

Item number two assesses important basic concepts and terminology.
Items like this are a means of quickly checking for a basic understanding of
scientiﬁc terms, formulas, etc.

Item number three is an enhanced multiple-choice question that

encourages and assesses higher level thinking skills. Enhanced multiple-choice

38

questions are more authentic than traditional test items in terms of the problems
they present and more challenging in terms of the thinking required to determine
the correct response. (Hart, 1994)

Items four, ﬁve, and six are examples of error analysis tasks. Error
analysis is an excellent example of how written assessment items can be used to
encourage higher-level thinking. Error analysis is an important part of true
scientiﬁc inquiry aid written post-assessments of labs are probably the most
effective, feasible means of doing this. Review of these error analysis items can
lead to some excellent post-lab discussions.

Item number seven shows how questions on a written assessment
measure the student’s ability to apply what they have learned in the lab to an
everyday world application. A question like this helps make the subject “real" for
the students and encourages thinking about the practical implications of
theoretical concepts. These questions are a favorite among some of my students
who are always asking, “Why are we studying this?”

Item number eight is an example of a question designed to evaluate
multiple skills such as the ability to interpret and organize data and the capability
to determine percent error. It evaluates higher level thinking skills such as those
involved with error analysis. It is also structured enough to be easily graded and
yet intricate enough that a student can not simply guess at the best answer.

The conceptualization activities that I used to check for higher level
understanding in my students took two different forms. In one form I had the

students answer theoretical questions related to a sample reaction.

39

Appendix E, part 6 is an example of this type of activity that I used following the
unit in which the class had discussed the activity series of metals, different types
of reactions.

This form of conceptualization activity is very simple to design and
present. It is simply a teacher demonstration modiﬁed to investigate deeper
understandings as a result of the style of questioning. This example illustrates
how conceptualization activities can be used to assess whether the students are
applying the higher level abstract concepts covered in lectures and textbooks to
practical demonstrations performed in the lab.

The second form of conceptualization activity I used involved
demonstrations that the students were required to perform and then explain. This
type of conceptualization activity is reminiscent of a performance task except that
the students’ ability to explain why the demonstration works or how it supports a
scientiﬁc theory is being assessed rather than the student’s ability to simply
perform the activity. Appendix E, part 7 contains an example of this type of
activity that was used to evaluate the students’ understanding of the atomic
theory of matter.

This form of conceptualization activity provides a rich experience — one
that is written, visual, and hands-on all at the same time. Its constructivist design
facilitates Ieaming even as the students are being evaluated making this a more
natural, embedded assessment. I believe this approach is more likely to trigger
deeper responses and provide a richer assessment of what the student truly

knows.

40

Development of lab practicals

Our school requires semester exams designed to hold the student
accountable for the semester’s content and encourage long-term retention of the
material. When suitably constructed, they can also be used to prepare the
students for standardized testing. In designing my semester exam I was strongly
inﬂuermd by the following three concerns:

1. The need to prepare the students for standardized testing.

2. The desire to provide an authentic assessment of what the students

have learned in the laboratory

3. The need to balance my high hopes for my students with realistic

expectations of their abilities.

In response to these concerns, I have divided my semester exams into
three parts. The students take one part of the exam every six weeks. Since the
last part of the exam relies on information from the beginning of the semester the
exam is still a cumulative test of what the student knows. This format seems to
greatly reduce the student stress. It also allows me to use a much larger, more
in-depth assessment than I would be able to if I used a traditional exam format.

The ﬁrst two parts of the exam, taken during normal class time in the 6‘“
and 12‘" week of the semester, are traditional paper-oriented tests similar to
standardized tests. These tests have a few basic questions, but most of the
items on these two tests are open-ended questions or enhanced multiple choice
questions. They provide a quick evaluation of the students’ content knowledge

and provide an opportunity for them to perform some additional writing in

41

science. For illustration, a portion of the written part of the second semester
exam has been included in Appendix F, part 1.

The third part of the exam is taken during the regularly scheduled two-
hour ﬁnal exam period assigned by the school’s administration. This part of the
exam is a laboratory practical based on the ideas of Robert Becker, (1995). It is
an open-book, lab-oriented series of activities designed to have the students
apply what they have learned in a meaningful way.

The practical evaluates the students’ ability to perform various scientiﬁc
activities in the lab. Appendix F, part 2 is a copy of the ﬁrst semester practical
exam and Appendix F, part 3 is a copy of the second semester practical exam.
The students are given a set of approximately ten lab activities that they must
accomplish within the two-hour block while working in small groups. These
activities cover a wide variety of topics and have a large range of difﬁculties. It is
deliberately too long for any individual student to complete so that the students
must work together as they divide their labors according to each student’s
expertise.

The students are assigned to homogeneous groups of four students
based on their semester’s academic performance in chemistry. Homogenous
grouping eases the expectations for the low achieving students who have already
found chemistry to be overwhelming. The strong science students who could
beneﬁt from being pushed to a higher level of competition ﬁnd this type of
grouping raises the expectations since they can no longer count on easy

opposition. This method of grouping is highly motivational since it makes it

42

possible for every student to earn a satisfying grade by providing realistic
expectations based on demonstrated student abilities. Homogeneous grouping
encourages every student to be accountable for the material since they are
grouped with others with no better command of the subject then themselves and
it reduces the stress within the group since the students end up grouped with
others having a similar work ethic.

This grouping results in the highest achieving students in each class being
grouped together. It also means that the lowest performing students are assigned
togetmr in a single group. Students are very concerned about this method of
assigning groups until they are assured that groups with widely differing scores
will not compete with each other. Instead the groups compete only with other
groups that are on their same level or tier. These tiers are composed of lab
groups with similar academic performances from all my chemistry classes.

The various lab groups and tiers are posted a week before the practical so
that students have time to organize themselves and their studies. Practice
worksheets, tasks, and labs are performed by each group the week before the
exam to review the necessary information and procedures. Students often use
this time to divide up work assignments and solidify individual responsibilities.

On the day of the test, each group of four students is given ﬁve copies of
the test - one white ofﬁcial copy and four colored work copies. All ﬁve copies
must be returned at the end of the practical, but only the single white ofﬁcial copy

will be graded. All work to be graded must be recorded on the ofﬁcial copy only.

43

The exams are then graded and the scores for each level are plotted on a
graph. This graph allows me to apply a best-ﬁt line to the data from all groups.
The intersection of this line with each tier is used as the denominator when
dividing the raw scores for each group in that tier. This determines the perfect
score for that level. This process results in an appropriate goal for each level with
higher expectations for the advanced groups. It makes a perfect 100% possible
for any group regardless of past academic performance. It also eliminates the
possibility of an unusually high score in a lower group artiﬁcially inﬂating the goal
for an entire tier.

Upon completion of the practical, the students are asked to evaluate their
lab partners and their contributions. Forewarning of this peer assessment
(especially following previous experiences with peer assessment) is a great
individual motivator for those students who might be inclined to do less than their
share of the work. This has the additional advantage of facilitating more

discussion and communication within the group.

Administration of posttests, surveys, and student interviews.

At the conclusion of this study all of the students were given a posttest
very similar to the pretest, as shown in Appendix G, part 1. They were also
encouraged to recall and rank the various lab assessment strategies using the
form in Appendix G, part 2. Each student was given a survey (Appendix G,

part 3), composed of twenty two open ended questions.

44

A series of interviews was also conducted with the students who
participated in the original interviews at the beginning of the study. The
information from all three of these instruments was used to evaluate the attitudes

of the students and the effectiveness of laboratory assessments.

45

Evaluation

This study was evaluated through the use of pretests, posttests, surveys,
interviews of students, and student assessments. These were used to evaluate
the effectiveness of the lab assessment strategies and the students’ attitudes
about them. This information allowed me to reﬁne and modify the activities to

more closely meet my objectives for doing them.

Pretests, Surveys, and Student Interviews

After the students had completed the pretests, their responses were
carefully examined for trends. Their responses were averaged to determine a
numerical value for the mean response to each statement. These values
indicated the students’ agreement with the statements on a scale of one to ten. It
is important to note that higher values connote a stronger agreement with the

statements. The results of this pretest are shown in Table 1.

46

Table 1 — Pretest Results

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Item # Statements Mean
Response

1. Science courses Should offer students lab activities. 9.6

2. I believe that lectures and discussions teach 4.5
chemistry more effectively than lab activities.

3. I think science courses should offer more lab 7.6
activities than they do.

4. I think that labs are more work than they are worth. 3.5

5. Lectures and labs in science courses are clearly 7.0
connected.

6. Science course laboratory work has increased my 8.2
understanding of how scientists actually work.

7. Labs make science more relevant to my life. 7.4

8. Lab work increased my interest in science. 8.1

9. Lab activities taught me more about science than the 7.3
book or lectures did.

10. I prefer open-ended investigative labs of my own 4.5
design.

11. Lab work improves my understanding of the material 8.1
covered in lectures.

12. Information from lab work should be a part of tests. 6.3

13. I prefer traditional written tests to nontraditional tests 4.3
that require me to do somethigg.

14. I concentrate more closely on lab work if I know I am 7.0
m be tested over the lab.

15. l have used laboratory notebooks to record labs in 4.9

 

science courses before.

 

 

47

 

The ﬁrst fourteen items on this posttest were designed to evaluate the
students’ impressions of the relevance and impact of lab activities in previous
science courses. The mean scores for these items Show that there is a favorable
understanding of the role that lab activities can and should play in science
courses. Items one and three indicate that the students are strongly convinced
that science courses should offer lab activities, and in fact, the study group’s
mean response indicates that teachers should increase the number of labs over
the around already curently employed. The responses to items two and nine
Show that the students initially felt that labs are moderately more effective than
lectures or discussions and signiﬁcantly more effective than bookwork at
teaching chemistry. The students’ general disagreement with item four shows
that the students consider lab activities well worth the efforts required by them.

The complimentary nature of the lab versus lecture approach to teaching
chemistry is reﬂected in the students’ response to number eleven, where the
students indicated their belief that lab work improves their understanding of the
material covered in lectures. Item ﬁve indicates that the students see a
cohesiveness between lab activities and lectures. In items six, seven, and eight,
the students’ mean responses indicate a favorable impression of the impact of
laboratory activities in connecting chemistry courses to the real world.

Item ten addresses the question of structured labs versus open-ended
labs. It is interesting to note that although the students are strongly in favor of

labs they are mildly disinclined towards open-ended labs. This initial impression

48

may be due to a lack of previous experiences with open-ended labs or perhaps
due to unfavorable past activities for some students.

The next few items were intended to gauge the students’ beliefs about
how the students would or should be assessed. Item thirteen shows a mild
disinterest in traditional testing whereas item twelve shows that the students
believe that information culled from lab activities is appropriate to evaluate during
tests. I believe that their mean response to this item is congruent with the
students’ belief expressed in item five that labs and lectures should be clearly
connected. Item fourteen alludes to a secondary reason for including laboratory
information on tests. Since the students indicated that they tend to concentrate
on the labs if they know they are going to be tested over the information, it makes
sense that we better include questions about the lab on future assessments.

Item ﬁfteen was designed to survey the students about their past
experience with that very common form of laboratory assessment - the
laboratory notebook. A mean response of 4.9 indicates that slightly less than half
the students participating in this study have had a past experience with

laboratory notebooks.

Surveys
All of the students participating in this study were asked to answer a series
of open-ended questions designed to provide them with an opportunity to

respond in greater detail than was available on the pretest. I used the students’

49

responses to ﬁfteen questions (Appendix A, part 2) to help interpret the numerical
data collected on the pretest.

The students’ responses to these questions were then carefully examined.
Based on these responses and academic performance, a smaller group of
students was selected for further interviews. These twelve students were broken
up into three groups:

Group 1: Successful students with grade point averages of 3.00 — 4.00

Group 2: Traditional students with grade point averages of 2.00 - 3.00

Group 3: Challenged students with grade point averages of 0.00 — 2.00.

Each of these students was asked in a face-to-face interview to explain in
detail their answers to the open-ended survey questions. I used this information
to further evaluate the students’ initial impressions of science and the role of
laboratory activities in science courses.

The ﬁrst three questions in the pretest were intended to determine the
general attitude of the students regarding science courses in general. The
responses indicated that the entire study group of 92 students had a fairly
positive impression of science, which is not surprising since this course is an
elective and is not required for graduation. Further interviews with the smaller
groups did reveal some differences pertaining to the most and least favorable
aspects of science. The Group1 students indicated that their favorite part of
science was the Ieaming about new things and the relationships to other events
and how they impact us. The Group 2 and Group 3 responses typically indicated

that their favorite aspect was the hands-on approach of science and seeing

50

something exciting happen. There was also a difference among typical
responses in regards to the least favorable parts of science. The Group 1
students commonly mentioned the monotony of some tasks while the Group 2
and Group 3 students almost universally indicated the amount of memorization
required in science courses as being their least favorite part. A telling response
scattered across the entire study group regarding the least favorite aspect of
science was summed up by the student who replied: “Learning about things that
probably won’t pertain to my future”.

Survey questions four through eight explored the perceived role of labs in
science courses. The students were overwhelmingly in favor of doing laboratory
activities in science courses. The Group 1 and Group 2 students explained that
the best part of doing labs was the way they (the labs) help us understand what
scientists do and how the labs pull the pieces together - relating science to real-
life situations. Group 1 students complained about the time-consuming nature of
labs as opposed to the rest of the students who did not have any clear common
negative response other than the obligation of cleaning up after a lab.

Question nine about laboratory notebooks had two very different
responses. I had anticipated on the pretest that the students would almost
universally indicate no prior experience with laboratory notebooks. However, the
results of the pretest, (4.9) was a very middle range response belying the polar
nature of the question. The students explained this unanticipated response by
indicating that one of the science teachers, who worked with almost half of my

students last year, had begun using laboratory notebooks in their biology course.

51

The question about student preferences regarding structured versus open-
ended labs drew a variety of responses. Many students answered that they
preferred structured labs for reasons including that structured labs “removed the
guesswork”, “leave less room for mistakes”, “are more structured”, and “they
reduce the chances that I will screw up”. Those students in favor of open-ended
labs rationalized their preference because “I can ﬁnd out what 1 want to know", “I
can see if I really understand the material“, and “open-ended labs are more
similar to what real scientists do”.

Questions eleven through fourteen asked for the students' opinions about
the frequency of labs and how they should be evaluated. While all of the students
wished to do lab activities often (usually more than two or three per week) there
was a difference in the strategies by which the students wished to be evaluated.
Group 1 students suggested more stringent evaluation strategies including
comprehension tests, percent error determinations, and the ability of the students
to apply what they had learned in the lab to other situations. Group 2 students
suggested a number of strategies including being evaluated on whether they
“knew what they were supposed to be doing". Group 3 students wished to be
graded on participation and the amount of “thought” they put into the lab rather
than on whether they were close to the correct answer. Group 3 students also did
not believe it would be appropriate to include lab-related information on tests.

In question ﬁfteen the students offered suggestions similar to many beliefs
reﬂected in the National Science Education Standards. The students wanted to

spend more time on fewer things so that they could Ieam more about them. The

52

students in all three groups wanted more labs and hands-on demonstrations to
help solidify their understanding of scientiﬁc concepts. Almost universally, my
students requested that I improve the connection between labs and lectures by
using numerous practical examples and daily demonstrations. Some suggested
that l reverse traditional teaching by using laboratory activities to teach the
course and lectures only when necessary to help tie together the main ideas
behind the labs.

This information from the pretest and survey suggests to me that the
students have a positive impression of science but are interested in changing the
way it is presented in the classroom. They want more relevant, hands-on

investigations and are willing to work for it.

Posttests, Surveys, and Student Interviews

The seventeen items of this posttest were designed to re-evaluate the
students’ impressions of lab activities following the implementation of this
intensive laboratory assessment study.

The student responses to the posttest were collected and carefully
analyzed. Their responses were then averaged to determine a numerical value
for the mean response to each statement as was done in evaluating the pretest.
These values indicated the students’ agreement with the statements on a scale
of one (strongly disagree) to ten (strongly agree). The mean results of this

posttest are Shown in Table 2.

53

Table 2 - Posttest Results

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Item # Statements Mean
Response

1. Science courses should offer students lab activities. 9.5

2. I believe that lectures and discussions teach 5.0
chemistq more effectiver than lab activities.

3. I think science courses should offer more lab 7.3
activities than they do.

4. I think that labs are more work than they are worth. 3.7

5. Lectures and labs in science courses are clearly 9.0
connected.

6. Science course laboratory work has increased my 8.4
understanding of how scientists actually work.

7. Labs make science more relevant to my life. 7.6

8. Lab work increased my interest in science. 7.9

9. Lab activities taught me more about science than the 7.0
book or lectures did.

10. I prefer open-ended investigative labs of my own 5.7
design.

11. Lab work improves my understanding of the material 8.0
covered in lectures.

12. Information from lab work should be a part of tests. 6.3

13. I prefer traditional written tests to nontraditional tests 4.0
that require me to do something.

14. l concentrate more closely on lab work if I know I am 7.9
going to be tested over the lab.

15. Laboratory notebooks helped me to understand the 6.7
labs better.

16. This science course offered more lab activities than 9.3
most science courses.

17. Lab assessments are harder than traditional tests. 5.1

 

 

 

54

 

Since the fourteen items are identical to those found in the pretest,
different mean scores should indicate changes in the student’s impressions as a
result of the strategies and procedures used in this intensive laboratory

assessment study. Figure 1 is a comparison of the results of the pre- and

 

 

 

 

 

 

 

 

 

posttests.
10
2 8 ‘
8 6 ‘9
a ‘2‘ IE
0 ,a p I _.
1 2 3 4 5 6 7 8 9 10 11 12 13 14

Question Number

 

 

 

Pre-test I Post-test!

 

 

Figure 1 - Average Pre 8. Posttest Responses

The responses to the statements showed little change between the
pretests and posttests for most items. This would imply that the use of multiple
laboratory assessment procedures did not incline the students to dramatically
change flair attitudes about these ideas. This may reﬂect the well-developed and
strongly held opinions about education found in students of this age group.

I did not ﬁnd the use of pretests and posttests very informative. They only
offered information about the students at the very beginning or end of the year.

This information was not very useful in developing day-to-day lesson plans.

55

Between these two tests, item five showed the greatest difference
(7.0 - 9.0) in mean scores of all the statements on the pre- and posttests. This
item asks the students to indicate their agreement with a statement about
whether lectures and labs are clearly connected. The responses indicated that
the students increased their impressions that there was a greater connectivity
between the different parts of the course. I believe that this very important
change was a direct result of using a systematic, comprehensive approach to
laboratory assessment.

The lack of a connection between labs and lectures has been a major
criticism of the hands-on approach to teaching. Because of this, it is imperative
that a stronger connection be forged to legitimize the use of lab activities in
science courses. This data suggests that a more careful, concerted approach to
lab activities and their assessments can create the connections we need to tie
the different parts of our science courses together into meaningful, cohesive
subjects.

Item ten’s small shift in preference (4.5 to 5.7) for open-ended labs was
meaninng to me. The shift from mild distrust to moderate acceptance of open-
ended labs suggests that further positive experiences would create a greater
willingness in the students to engage in laboratory activities of their own design.
Though Group 1 students were the most successful in open-ended labs, they
were also more likely to voice a concern about the lack of guidance provided by

open-ended labs.

56

During the course, the general attitude of the classes towards open-ended
labs changed, as the students became more accustomed to them. At ﬁrst, the
students started open-ended labs quietly, waiting for the class leaders to provide
some sort of initial direction. By the end of the study, open-ended labs would
start almost explosively as students excitedly started the lab according to their
designs. Whereas traditional labs seem imbued with a sense of purposefulness,
open-ended labs are more often characterized by “Wonderment'. Open-ended
labs are exciting to watch and produce a large number of new Ieaming
experiences for everyone.

Posttest items ﬁfteen, sixteen, and seventeen provide some important
information to be considered for evaluating the effectiveness of laboratory
assessment. In item ﬁfteen, the students indicated a connection between the use
of laboratory notebooks and their understanding lab activities. The mean
response to this statement (6.7) indicated that there was a strong belief that the
use of laboratory notebooks furthered understanding of the labs. Students do
complain a little about the amount of writing and preparation they must perform
prior to the lab - something that I didn’t hear when I used data sheets and
cookbook labs. However, I have far fewer students who do not know what they
are supposed to be doing during labs. This results in a greater number of
students on task for a larger amount of time, and a safer laboratory environment.
It became clear during the interviews that there was a strong correlation between
student preference for laboratory notebooks and student achievement.

Successful students valued and relied on their lab notebooks while academically

57

challenged students tended to disregard their notebooks. Successful students
had better notes from previous labs to refer to when questions arose during a
given lab activity. Students who tended to underrate the value of their lab
notebooks had poorer write-ups resulting in lower grades on current assignments
and poorer examples when working on future lab assignments.

Item sixteen’s mean score of 9.3 was predictable in view of my
predilection for laboratory activities. The students were involved in either major or
minor lab-related activities almost daily. This has helped to make the course very
popular with the students. I believe that this also helps to explain the very low
absence rate for students in this course. The combination of high success (over
93% of the students successfully pass the course), popularity among the
students (creating a waiting list to get into the course), and unusually low
absenteeism helps the administration to justify the expense involved in this
laboratory oriented course.

The students indicated in item seventeen with a mean score of 5.0 that
there is no signiﬁcant change in the difﬁculty associated with laboratory
assessments. They indicated a very balanced reaction to a statement attempting
to determine whether they felt laboratory assessments were harder than
traditional tests.

I found the interviews were more valuable than the pretests and posttests
because they supplied greater insight into the students’ perceptions of the lab

activities and provided timely feedback with which to adapt my teaching methods.

58

Their observations were useful in determining the speciﬁc effectiveness of each
lab activity and the general attitudes of the students to the entire course.

In the interviews, the students strongly supported the idea that labs are a
very important part of a science course. The students suggested that some form
of chemical demonstration or practical application should be incorporated into
every lesson. They also continued to support the idea that lab work improves the

students’ understanding of the material covered in lectures.

Assessment Strategy Evaluation

The students were asked to evaluate the various assessment strategies
used during this course for their effectiveness and enjoyment. This evaluation
can be found in Appendix G, part 2. The responses to this evaluation were
compiled and averaged (Table 3). The students in the three in-depth study

groups were also interviewed and asked to explain their responses in more

detail.

59

Table 3 - Laboratory Assessment Strategy Evaluation

 

 

 

 

 

 

 

 

 

 

 

 

Evaluation Teaching Personal

Laboratory Assessment Strategy Effectiveness Effectiveness Enjoyment
Laboratory Notebooks 7 8 7
Performance Checklists 10 4 7
Student Interviews 9 5 6
Peer Assessments 8 6 6
Performance Tasks 8 9 9
Open-Ended Labs 9 9 8
Teacher Demonstrations 8 9 9
Written Assessments 8 7 5
Conceptualization Activities 7 8 7
Lab Practicals 9 8 7

 

 

 

 

The data in Table 3 suggests that the students felt that laboratory

notebooks effectively evaluate what the students have learned. Interviews

substantiated this conclusion, but students in Group 2 and Group 3 also

suggested that these notebooks Should be graded Ieniently. They felt that the

ﬁnal grade should be based on the students’ abilities to do the lab and

understand its message rather than on their ability to get the “right answer”.

The students indicated that laboratory notebooks were a more effective

tool for teaching than they are for evaluation. By requiring the students to write

out the procedures and construct their data tables ahead of time the students

60

 

developed a better understanding of what they were doing in the lab and why
they were doing it. The high personal enjoyment score given to the laboratory
notebooks reﬂects the natural appeal that lab activities have for many students.

Performance checklists were recognized by the students for their obvious
evaluation merits. These were given the highest ranking for evaluation
effectiveness of all the different laboratory assessment strategies. They were
also given the lowest ranking for teaching effectiveness due to their inability to
teach new information. Students indicated that they appreciated performance
checklists on both the written evaluation and in their interviews. The students
commented that checklists seemed like a very clear and straightforward form of
assessment.

The next form of assessment was the student interview or interview sheet.
The students indicated that they believed these interviews were very effective for
evaluating what the students have already learned. I would concur that this form
of assessment is very informative and provides an extremely rich form of
assessment This tool provided detailed feedback that strongly inﬂuenced my
teaching strategy as I planned future lessons. The drawbacks to this form of
assessment lie in its limited potential to teach new material and its time-
consurning nature. While the written student interviews met with only moderate
appreciation, the face-to-face verbal interviews were very pleasant for both the
students and the teacher.

The data from Table 3 shows that peer assessments earned high marks

for their ability to effectively evaluate the students. It increases student

61

accountability while providing a richer, more authentic assessment of what is
actually occurring in the lab. Peer assessments are not well suited for providing
content Ieaming opportunities. They can give the students experience at
assessing coworkers and help teach students about responsibility and teamwork.

The students varied widely in how much they enjoyed using peer
assessment. Individual scores for the enjoyment factor associated with peer
assessment ranwd from very low (ones) to very high (tens). In the interviews
some students stated that they did not feel qualiﬁed to judge their lab partners,
nor did they feel that they were evaluated justly by others. Other students derived
real pleasure from evaluating their peers since they felt they could hold their
partners truly accountable for their share of the workload. Peer assessments
were considered to be the most fair when homogeneous lab groups were created
by the teacher before the lab started.

Performance tasks received strong endorsements from the students in all
three categories. The students felt that they were highly effective at both
measuring what they had learned as well as teaching them new material. The
personal enjoyment was audibly evident as the volume and excitement increased
when the students engaged in a performance task as part of a test. Students
spoke of looking fonivard to the tests because of their curiosity about what the
performance task would be for that particular unit.

Open-ended labs also received high marks for all three areas. They were
considered to be equally strong at measuring what the students knew and at

providing new Ieaming opportunities. All three of the in-depth study groups

62

included strong advocates for the continued use of these types of labs. Many
suggested that they enjoyed devising their own procedures and Ieaming about
what they wanted to know. A few students did indicate, to the contrary, that they
did not enjoy the lack of structure inherent to open-ended labs and found them to
be stressful situations.

Demonstrations are a very successful teaching strategy. They can also
be modiﬁed into an effective form of assessment by having the students explain
the mumstration instead of the teacher. This technique gives us an effective,
new form of assessment without diminishing an already-existing, successful
teaching strategy. Teacher demonstrations were considered to be quite effective
at assessing students’ knowledge. It is interesting to note that the students felt
that teacher demonstration assessments were also effective at teaching new
material.

Students stated that the demonstrations provided strong clues and
backgrounds for the questions they were asked to answer on tests. In interviews,
the students remarked about how exciting teacher demonstrations were. This
was due to the fact that the simpler and safer demonstrations were typically
transformed into student performance tasks.

When given a written assessment, the classroom typically became very
serious and studious. The students applied themselves more thoughtfully and
with greater commitment than they usually did when taking traditional tests.

Students also indicated that they were not especially fond of written assessments

63

 

because they were similar to conventional tests and because they “forced the
students to think too hard".

Conceptualization activities were considered effective and enjoyable. The
academically successful students of Group 1 were the most favorably inclined
towards these activities since these activities often asked the students to step
back and explain something in terms of the bigger picture. The Group 3 students
found conceptualization activities to be enjoyable but somewhat disconcerting
since the questions were sometimes “a little too abstract”.

Laboratory practicals were also very effective assessment strategies.
They posed numerous opportunities for students to demonstrate their knowledge
on a variety of levels. They could incorporate almost all of the other forms of
laboratory assessment and do so in a situation ripe with new Ieaming
opportunities. Students indicated that they enjoyed these practicals much more

than traditional tests.

Discussion and Conclusions

As a result of this study, I am convinced of the validity and the
effectiveness of laboratory assessment in the chemistry classroom. A
comprehensive approach to the systematic evaluation of the Ieaming that occurs
in the lab holds signiﬁcant beneﬁts for both the students and the teacher.
Embedded laboratory assessment offers engaging Ieaming opportunities for the
students at the same time it appraises their knowledge of both material and
processes. The authentic nature of laboratory assessment helps prove to the

students the relevance of chemistry concepts in the real world. Thorough use of

64

_

.Jr

laboratory assessment validates the use of lab activities by the students as it
simultaneously provides a deeper, richer assessment of the students’ abilities.

It is important to note that no single part of the laboratory assessment
model offered in this study is the best for all situations. I feel that a thoroughly
planned, carefully implemented combination of most or all of these strategies will
have a positive effect on the learning, assessment, and atmosphere of most
chemistry classrooms. Since there are many different aspects of laboratory
assessment, teachers wishing to incorporate aspects of this strategy will have to
carefully analyze their speciﬁc objectives for each lab activity. In the following
sections, I will attempt to summarize my findings individually for each of the

major components of laboratory assessment.

Laboratory Assessment Strategies Used During Laboratory Activities

Laboratory Notebooks

The initial response to lab notebooks was one of dread. Initial student
interviews suggested that the students were concerned about my expectations
when grading these notebooks. They were also worried about the time and labor
required to produce presentable lab notebooks since they require much more
time to complete than lab worksheets, which require essentially no time at all to
complete.

As the students become more proﬁcient at writing lab reports they require
less and less guidance. The need for the teacher to spend time rewriting lab

procedures will gradually diminish until it reaches the point where the students

65

can be handed a standard “cookbook” lab from almost any lab book and they will
still be able to convert it into the desired lab report format.

Lab notebooks are also more cumbersome to use than the traditional data
sheets that can be copied or torn out of publisher’s lab books. My standard 100-
plus stack of lab notebooks is approximately two feet tall and not very
transportable. l established a speciﬁc location for students to periodically turn in
their notebooks when either they or myself felt the need to evaluate their
performance.

Lab notebooks were occasionally more confusing than data sheets, until
the students learned the need to adhere to a standard format. With abundant
feedback on early lab reports and clearly stated expectations, most students
developed very acceptable lab notebooks. I found it helpful to require an up—to-
date table of contents page in the front of the notebook. The use of lab
notebooks was also made easier by developing a regular routine of when lab
reports were to be submitted for evaluation.

I believe the use of laboratory notebooks provided a more authentic
laboratory experience bearing greater similarity to the labs my students will
experience in college and in the workplace. In their interviews, a number of
students indicated that this greatly enhanced the value and relevance of the labs.

I believe the students came into the lab better prepared to safely get to
work and had a more meaningful experience as a result of writing their lab
reports. The students often surprised me with their reﬂections and gave me clear

indications of what they knew and still needed to Ieam. In their reﬂections the

66

students often included important secondary beneﬁts to performing a lab.
Examples of some of these reﬂections taken from lab notebooks are:
“Hot glass looks like cold glass.”
“Acid burns don’t cool down like heat burns — at least not until you wash
off the acid.”
“I didn’t know that so many things are acids.”

Laboratory notebooks gave me an assessment tool that provided a
long-term record of the students’ performance throughout the course. As a result
of using laboratory notebooks, l was able to ask more of my students and receive
more in return. This was a great improvement over what I was able to do when I
used publisher’s lab sheets or data sheets. Consequently, I strongly recommend
the use of laboratory notebooks. I would encourage the teachers who use them
to consistently drill and reinforce in their students the need for neatness and

correct format.

Performance Checklists

To create a performance checklist, a teacher must identify the important
behaviors or steps during a lab that they wish to observe their students
performing. It is important not to attempt to evaluate too many steps during the
lab since it will be difﬁcult to observe all of the students as they proceed through
the lab at different speeds.

The obvious use of performance checklists sent a subtle but clear

message to my students about what I considered important. It was interesting to

67

note the difference in their behavior when they felt that l was closely watching
them. The use of performance checklists targeted behaviors I wished to evaluate
and simultaneously identiﬁed for the students those behaviors that they needed
to change if they were substandard.

Students that typically do well on written tests also performed very well in
the lab. I expected to see evidence that some students that did not test well
would perform, as well, or better than their peers in the lab. I did not see any
evidence of this. Those students that tended to be confused or disengaged
during lectures were similarly at a loss during lab activities. Students that tended
to be sloppy or haphazard in their paperwork had a Similar sloppy, haphazard
approach to labs. In view of the current publications on multiple Ieaming styles, I

feel that this is surprising and worth further study.

Interview Sheets

Interview sheets provide feedback to the teacher about student
perceptions regarding classroom activities. They can be time consuming and
therefore work best with small representative samples of students that the
teacher has already identiﬁed as being indicative of larger groups.

My experience indicates that interview Sheets are more successful when
the students are asked to respond in writing and then asked to verbally explain
what they meant. The students are sometimes surprising in the clarity or depth
with which they express themselves orally. Interview sheets can also be used as

an opportunity for the students to practice writing in science classes. The process

68

of writing responses to higher-level questions posed by interview sheets can also
help the students transfer information leamed in the lab to everyday world
applications.

I found that by identifying students that are inclined to give clear, detailed
feedback, (either positive or negative) the teacher gains an important tool for
evaluating the Ieaming in the lab. Their perceptions can also be used to judge

the validity of performing a speciﬁc activity again in the future.

Peer Assessment

When using peer assessment, I always gave both members of a lab group
the opwtunity to evaluate both themselves and their lab partner. I found it
beneﬁcial to include a comment section in which the students were asked to
explain their evaluations. These comments often led to some interesting and
frank discussions about the different roles students performed or were expected
to fulﬁll during a lab activity. It was interesting to note the honesty and similarity
of the peer assessments within each lab group.

I would encourage the regular use of peer assessments in any laboratory
course. It allows the teacher to see and evaluate the students from another point
of view. It also offers the students valuable opportunities to practice evaluating
their peers and learn in a more authentic manner the appropriateness of their

contributions and work ethic.

69

Laboratory Assessment Strategies Used After Laboratory Activities

I used the following laboratory assessment strategies in conjunction with
traditional tests to evaluate what the students have learned at the end of a unit.
These forms of laboratory assessment indicate the students' exit knowledge and

what they have learned and retained as a result of the lab activities.

Performance Tasks

The students were particularly fond of teacher demonstrations as
performance tasks. They enjoy the exciting nature of these demonstrations. As
the students perform and explain these demonstrations they also provide some
important feedback to the teacher on whether the students are “really getting it”

when we talk discuss chemical demonstrations.

Open-ended Labs

While most lab exercises provide the students with carefully detailed
instructions for every step, open-ended labs require the students to design their
own procedures. As the students became adjusted to open-ended labs, the
number of students who strongly preferred detailed, traditional labs slowly
decreased. Frank discussions about my expectations and the grading eased
some of the students’ fears. By creating challenging and exciting open-ended
labs, I attempted to increase the students’ preferences for open-ended labs. I did
this because I believe that open-ended labs encourage higher level thinking

skills.

70

I highly recommend the use of rubrics to facilitate the assessment of open-o
ended labs. The process of developing a rubric for the lab will help crystallize the
teacher’s objectives for doing the lab. It will also help to identify potential trouble
spots that may require guidelines for the students. These guidelines should be
used sparingly to maintain the integrity of the open-ended assessment. However,
they may be necessary to help communicate the teacher’s intentions or to avoid
potential health hazards. It is advisable to share the rubric with the students
before they start the activity to help provide some framework.

Students will need some introduction to the open-ended lab. This V
introduction typically provides some background, a timeline, the appropriate
rubric, some equipment or materials boundaries, and some safety guidelines.
These introductions can become less detailed as the students become more
familiar with the process. Appendix H, part 1 is an open-ended lab assessment
and rubric designed to evaluate a student’s ability to write and perform a
chemical bonding investigation. This particular open-ended investigation is
unusual since it does not require the students to perform the investigation. Close
inspection of the rubric shows that this activity is evaluated only in terms of the
student's report. However, all of my students did chose to perform the lab even
though it was not absolutely required. Appendix H, Part 2 contains the directions
and rubric for the very popular Eggsplosions Open Ended Lab Activity. This
activity is very exciting, but it requires very close supervision on the teacher’s

part.

71

Teacher Demonstrations

My students indicated a strong preference for this form of laboratory
assessment. They said that teacher demonstrations made the tests more
exciting. In interviews and informal discussions they spoke of how these
demonstrations provided the real-world connections that made the scientiﬁc
concepts seem important and relevant. By carefully designing the questions to
build on what they saw in the demonstration, I was able to encourage the
students to look beyond the book for everyday implications.

Many chemistry teachers have large collections of educationally valuable
demonstrations that they would like to share with their students but are not able
to because of time constraints. Some of these time restrictions are
subconsciously self-imposed by the teacher who has failed to see that these
demonstrations can be used to both teach and evaluate the students. A strategy
that I found to be very successful was to use one demonstration to present a
scientiﬁc concept and, later in the unit, another related demonstration to see if

the student actually internalized the information from the ﬁrst demonstration.

Written Assessments

Proper written assessments are challenging to write but very easy to
grade. The difﬁculty in writing them stemmed from my need to make sure that I
wasn't writing another “standard” test. I had to write every item from scratch. The
process was time-consuming because I had to present the students with real

data, and in some cases, realistic looking miscalculations, for them to analyze.

72

Written assessments worked best when they included a variety of
questions that evaluated the students on a number of levels. The students who
took their labs seriously tended to do very well on the data analysis and error
analysis sections of the written assessments. The questions that related the lab
to everyday applications often prompted classroom discussions.

Initially I had intended the students to complete written assessments
individually. However, I eventually found that they were also conducive to small
group activities as well. The discussions that occurred within these small groups

were very rewarding for the students and informative to me as their teacher.

Conceptualization Activities

I believe most teachers would ﬁnd this form of assessment very valuable
since it is designed to evaluate a student’s deeper understandings. I found that
conceptualization activities could easily detect and identify major underlying
misconceptions. These mistaken beliefs were then corrected through the use of
other activities and the students’ understanding of the world fundamentally
changed.

It is entertaining and illuminating to watch students attempt to explain the
rﬁscrepant events commonly found in conceptualization activities. For example, it
is surprisingly educational to have students:

- watch boiling water and ask them to explain in detail What is in the

bubbles.

73

- discuss how atoms are mostly empty space and then ask them to
explain why they can stand on the ﬂoor without simply having their
atoms fall through the atoms of the floor.

- watch and explain why a beaker of water in a partial vacuum boils

and eventually begins to freeze simultaneously.

Lab Practicals

The use of laboratory practicals as part of my ﬁnal exam has dramatically
changed and improved my course. These practicals were an incredibly powerful
form of assessment that was very popular with my students. Many students
commented that their chemistry ﬁnal, including the lab practical, was their favorite
exam. They said that the lab practical format reduced their stress levels and
made the exam more cooperative than competitive. This was conﬁrmed by the
exceptional teamwork and cooperation demonstrated by students of all ability
levels during these practicals. I really enjoyed using this format with its
homogenous grouping of students for my final exam. It lowered the students’
stress, improved their assessment, and streamlined the paperwork.

The students need a lot of time to prepare for practical exams. They need
the time for reviewing and practicing important laboratory procedures. They also
need time to coordinate their responsibilities within the groups. This is not “down
time“, time that is “wasted” on review instead of Ieaming new ideas. My
experiences during this study indicated that some of the best Ieaming in the

classroom occurred during this review section as the students reacted to the

74

pressure of the impending exam and taught each other important lab procedures
and scientiﬁc concepts.

I found that it was helpful to present a series of labs, tasks, and
worksheets to the students the week before the exam. These activities were
similar in design to the tasks the students would be required to perform during
the exam. This series of activities encouraged the students to engage in the
learning/review session. The students found that this review session also
identiﬁed my expectations and indicated the level of expertise I expected of my

students.

Summary

During this study, I discovered and documented the effectiveness of using
lab related activities to evaluate almost all aspects of a chemistry course. I
believe that these assessments give me more detailed information about my
students and what they have learned, than any other evaluation strategy I have
ever encountered.

As a result of switching to this lab based assessment process I have seen
an improvement in my students’ abilities to use and understand chemistry. At the
end of the year I ﬁnd fewer students that are easily stumped by simple
demonstrations of chemistry in the everyday world.

The use of systematic laboratory assessment requires a lot of time, work,
and preparation — but it is well worth the effort. In the long run, this process of

using lab based assessment does not dramatically increase the amount of time a

75

teacher spends on grading. Rather it shifts the time and focus of current
assessment activities away from an over reliance on pen and paper tests
towards a more hands-on approach to evaluation. I would strongly recommend a
similar comprehensive laboratory assessment process for other chemistry
teachers who wish to either replace or augment their current assessment
procedues.

In Appendix I, parts 1 - 17 l have included a variety of other laboratory
assessment activities that I used during this study. These assessments were not
directly referenced in this thesis because most of them represent a blending of
several evaluation strategies. I thought it would be helpful to include these
sample assessment activities to demonstrate more of the many forms of

laboratory assessment.

76

Appendices

77

Appendix A

Pretest and Survey

Part 1 - Pretest

Please indicate how much you agree with the following statements. Base your

answers on this science course only. Record your answers by circling a number

from one to ten. Circling a one means that you strongly disagree and circling a

ten means you strongly agree.

1.

N

Science courses should offer students lab activities.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
I believe that lectures and discussions teach chemistry more effectively
than lab activities.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
I think science courses should offer more lab activities than they do.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
I think that labs are more work than they are worth.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
Lectures and labs in science courses are clearly connected.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
Science course laboratory work has increased my understanding of how
scientists actually work.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
Labs make science more relevant to my life.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)

78

8. Lab work increased my interest in science.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
9. Lab activities taught me more about science than the book or lectures did.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
10.! prefer open-ended investigative labs of my own design.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
11. Lab work improves my understanding of the material covered in lectures.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
12.! prefer traditional written tests to nontraditional tests that require me to do
something.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
13. Information from lab work should be a part of tests.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
14.! concentrate more closely on lab work if I know I am going to be tested
over the lab.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
15.l have used laboratory notebooks to record labs in science courses

before.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)

79

95.09.09!”

10.
11.
12.

13.
14.
15.

Appendix A

Pretest and Survey

Part 2 - Survey
Do you enjoy science?
What do you enjoy the most about science?
What do you enjoy the least about science?
Do you enjoy labs?
What is the best part about labs?
What is the worst part of labs?
Why do we perform labs in science courses?
Are labs necessary?
Have you ever used a lab notebook before?
Do you prefer very structured labs or open ended ones? Why?
How often should students perform lab activities during a science course?
How should teachers evaluate the Ieaming that occurs during lab
activities?
Should questions about recent labs being included on tests?
Should tests include lab activities?

How should teachers improve the connection between labs and lectures?

80

Appendix 8
Laboratory Reports

Part 1 - Report Format

 

 

Title of Laboratory Activity

Pumas of the Investigation:
This statement summarizes the reason for doing the lab.

Procedure:

This is a sequence of the important activities in the investigation.

Observations and Data:

These are descriptions of what has occurred in the course of the investigation.
Observations are qualitative statements that describe things such as
odors, colors, gas or precipitate formation.

M are quantitative observations collected during the experiment. The
number of signiﬁcant digits used in data collections needs to match the
tolerance of the instrument used. Data should be legible, recorded i
appropriate table form, and properly labeled. Erasures are not allowed.
If an entry needs to be corrected, draw a line through it, then enter the
correct data.

Calculations, Results, and Questions:

These processes occur after the data is collected.

Calculations are any mathematical manipulation of data that help
answer the central question or clarify the purpose of the investigation.
Results are summary statements of the data. Results could be
statements that show patterns, statements that reﬂect relationships
between variables, or graphs that show the relationships between
variables.

Questions ae often assigned to help you connect the lab with important
concepts and to help you apply what you have learned to the real
world.

Conclusion:

This statement ties the purpose to the results of the investigation.

Reﬂection:

Students should assess their own thinking strategies.

Complete one of the following stems:
One thing I learned that I did not know before is
One thing that really surprised me is
One thing that I will remember ﬁve years from now is

 

Figure 2 - Laboratory Report Format

81

 

Appendix B
Laboratory Reports
Part 2 - Notebook Instructions

Students should maintain a table of contents in the front of the notebook
that lists where all labs can be found.

Your Chemistry Notebook will become a written record of the many
experiments, demonstrations, and investigations that you will be
completing in this class. The most frequent entries in this notebook will be
Laboratory Reports. Laboratory Reports are formal written recordings of
the procedures and outcomes of lab investigations. They MUST be written
out according to the established laboratory report format.

Write all information from labs directly into the laboratory notebook, not on
a scrap of paper to be entered later.

Lab notebooks require the use a ballpoint pen.

Wrth the exception of the data table — complete sentences, proper spelling
and correct grammar should be used at all times.

Rather than assign a poor grade to a report, I may ask you to rewrite it. No

grade will be recorded until the rewritten report is returned.

82

Appendix 8
Laboratory Reports

Part 3 — Rationale for using Laboratory Notebooks

Formal laboratory reports are similar to the records kept by professional
scientists and are a very real part of “doing" science.
Laboratory reports act as a chronological record of successful procedures
that can be reviewed when later, open-ended experiments are being
designed by the student.
The data and observations from earlier experiments may prove to be a
valuable source of “proven” data that later labs or lab assessments will
build upon.
Formalized lab reports encourage awareness of appropriate procedures
and safety precautions.

Lab reports encourage the development of good writing and reporting
skills.
Rewriting the procedures helps develop the students’ abilities as critical
readers.
The process of writing and then using procedures written by the student
demonstrates the subtle intricacies and advantages of efﬁciently designed
lab notebooks.
Lab reports avoid the “cookbook” feel of the ﬁll-in-the-blank lab sheets

found in textbooks.

83

0 Lab reports should make students fundamentally aware of “why we are
doing this” and how the lab is not an intrusion in the unit but actually the
“proof’ of what we are studying.

. By designing their own procedures and data tables, students practice
higher level thinking skills as they interpret, analyze and deduce their own

conclusions.

84

Appendix 8
Laboratory Reports

Part 4 - Sample Lab Report

Chemical Analysis of Bug Juice

Purpose: To determine the squish value of bug juice

Procedure: 1.

2.

Collect and sort ants according to species.
Determine the mass of the ants.
Squish the ants using a mortar and pestle.

Test the squish with pH paper to determine the acidity of the
bug juice.

Calculate the squish value using the appropriate data.

Table 4: Bug Juice Data Table

 

Mass (kg) Acidity (pH) Observations

 

 

.0015 4.7 when ground with

Ants were squished

 

 

 

mortar

 

Calculations and Questions:

pH = mzlsquish= (.0015 kg)2l4.7

Squish = mzlpH= 4.8 x 10'7 kg2

Question 1. Which ants appear to have the highest squish coefﬁcient?

Conclusion: The squish value of the bug juice appears to be related to mass
and inversely proportional to pH. There also seems to be a variation in the squish

Red ants have a higher squish coefﬁcient than do black ants.

value among different ant species.

Reﬂection: One thing that I learned that I did not know before is that since the
ants wiggled and squirmed and in general tried to escape, I concluded that ants

do not like to be squished.

85

Appendix C
Alkaline Earth Metal Lab

Part 1 — Unmodiﬁed Lab as Found in “Typical” Lab Manual

Investigate some reactions of some Group 2 elements and gain some insights

into the properties of these alkaline earth elements.

Materials
calcium tumings (Ca) Saturated solutions of:
magnesium ribbon (Mg) calcium hydroxide (Ca(OH)2)
magnesium sulfate (MgSO4) magnesium hydroxide (Mg(OH)2)
calcium sulfate (CaSO4) barium hydroxide (Ba(OH)2)
barium sulfate (BaSO4) 1 Molar solutions of:
distilled water sodium carbonate (Nazcoa)
phenolphthalein solution magnesium chloride (MgClz)
calcium chloride (CaClz)
barium chloride (BaClz)
Procedure
PART A

1. Pour about 5 ml of distilled water into a clean, dry test tube and place the test
tube in the test tube rack. Add a calcium turning to the water in the tube. To
collect the gas being released, invert a clean, dry tube over the reactant tube,

holding the inverted tube with a test tube holder.

86

2. Test for hydrogen by inserting a burning wood splint into the upper end of the
inverted tube.

3. Add one drop of phenolphthalein to the solution in the reactant tube. After
making your observations, discard the contents in the tube and then clean
and dry the tube.

4. Repeat step 1, using a 10cm piece of magnesium ribbon in place of calcium.
If no visible reaction occurs, heat the water to boiling, using a test tube holder
to hold the tube over the burner ﬂame. CAUTION: Point the tube away from
yourself and others while heating.

5. Once the water is boiling, stand the tube in a test tube rack and, using a test
tube holder, invert a collecting tube over the reactant tube. Record your
observations. Discard the contents of the tube, and clean and dry the tube.

6. Turn off the burner and add a few drops of phenolphthalein to the reactant
tube. Record your observations. Discard the contents of the tube, and clean
and dry the tube.

PART B

7. Obtain 5-ml samples of saturated solutions of calcium hydroxide, magnesium
and barium hydroxide. Test each solution with pH paper. Record the pH of
each solution.

PART C

8. Using the laboratory balance, measure .out a 1-g sample of magnesium
sulfate. Place it in a clean, dry test tube.

9. Repeat step 8 for calcium sulfate and barium sulfate.

87

10.Add 5-ml of distilled water to each tube. Using a glass stirring rod, stir each
mixture thoroughly, getting as much of each solid to dissolve as possible.
Record your observations of the relative solubilities of each of these
compounds.

11.Conduct a ﬂame test for calcium ions (Ca2*) and for barium ions (Ba2”). Dip
the wire loop of the tester into the solution of calcium sulfate. Place the loop
in the burner ﬂame. Observe and the color of the ﬂame. Clean the loop and
repeat using the barium sulfate solution.

PART D

12.Stand 3 clean, dry test tubes in the test tube rack. Using the 0.1 M solutions,
add about 5 ml of the MgCl2 solution to one tube, 5 ml of the CaCI2 solution to
a second tube, and 5 ml of BaCI2 to the third tube.

13.To each of the solutions in the test tubes, add about 1 ml of the Na2003
solution. Record your observations.

Data PARTA

Ca + HOH:

Result of test for H2 gas:

 

Result of adding phenolphthalein

 

Mg+HOH:

Result of test for H2 gas (before heating)

 

Result of test for H2 gas (after heating)

 

Result of adding phenolphthalein

 

88

PART 8

pH readings:
Mg(OH)2 Ca(OH) Ba(OH)2

PART C

Apparent solubility: Flame test results:

MgSO4 Ca2+

 

CaSO4 Ba2+

 

38304

PART D

Observations:

 

Conclusions and Questions

1.

Write balanced equations for each change that occurred as part of
this experiment in steps 1, 4, 10, and 13.

Describe the reactivity of the Group 2A metals due to their location
in the group.

How does the reactivity of an alkaline earth metal compare with that
of an alkali metal (Group 1) in the same period?

What oxidation states can the alkaline earth metals eidtibit?

Why does the metallic character of the alkaline earth metals

increase as you go down the group?

89

Appendix C
Alkaline Earth Metal Lab

Part 2 — Lab after being Rewritten into Pre-Lab Format
Pre-lab Discussion:

In this lab you will be studying the chemical reactivities of the 2"“I Family of
elements on the Periodic Table. You should notice both a general similarity in
properties and a trend of increasing reactivity as we move down this family.
Group 1A -the Alkali Metals would show similar but more dramatic reactivities,
however, they are actually so reactive as to make them unsafe to use in the lab.

The elements in Group 2A of the Periodic Table are called the Alkaline
Earth Elements. The elements in Group 2A are chemically active and are never
found in nature in the elemental state. Like all members of a group, or family, the
elements in Group 2A share certain common characteristics.

The metallic character - the tendency to donate electrons during chemical
reactions - of the Group 2A elements increases as you go down the group. The
more metallic of these elements typically react with water to form hydroxides and
hydrogen gas. An example of such a reaction would be:

Cam + 2HOH 9 Ca(OH)2(.q,+ Hm,

As metallic character increases (as you go down the group), the tendency
for these elements to form ions increases. Also as you go down the group, the
solubilities of the hydroxides formed by the elements of this group increase. The

more active the metal, the more basic its saturated hydroxide solution.

90

The solubilities of Alkaline Earth compounds also show some interesting
and useful tendencies. For example, the sulfate compounds of Alkaline Earth
Metals Show decreasing solubilities as you go down the group. This
characteristic is used as a means of separating and identifying metallic ions of
this group. Carbonates of all Alkaline Earth Metals are quite insoluble.

Purpose of the Investigation:

To investigate some reactions of some Group 2A elements and gain some

insights into the properties of these Alkaline Earth elements and the trends we

see in these properties as we move down a family on the periodic table.

Equipment

balance test tube rack ﬂame tester
burner wood splints ﬁlter paper

test tubes,(3) pH paper safety goggles
test tube holder stirrer lab coat or apron
Materials

calcium tumings (Ca) Saturated solutions of.
magnesium ribbon (Mg) calcium hydroxide (Ca(OH)2)
magnesium sulfate (M9804) magnesium hydroxide (Mg(OH)2)
calcium sulfate (CaSO4) barium hydroxide (Ba(OH)2)
barium sulfate (BaSO4) 1 M sodium carbonate (Na2003)
distilled water 1 M magnesium chloride (MgCl2)
phenolphthalein solution 1 M calcium chloride (CaCI2)

1 M barium chloride (BaCl2)

91

Safety

Handle all chemicals with care; avoid spills and contact with your skin.

Heat chemicals exactly as instructed. When heating a substance in a test

tube, point the tube away from yourself and others. Tie back long hair and

secure loose clothing when working with an open ﬂame. Always wear

safety goggles when working in the lab.

Procedure:
Part I

1.

Pour about 5 ml of distilled water into a test tube and stand the tube
in a test tube rack. Add a calcium turning to the water in the tube.
To collect the gas being released, invert a test tube over the
reactant tube, holding the inverted tube with a test tube holder.

Test for hydrogen gas by inserting a burning wood splint into the
inverted tube.

Add a Single drop of phenolphthalein to the reactant tube and
record your observations. (Phenolphthalein is a base indicator and
will turn bright pink if it detects the presence of the hydroxides
which are found in a base. As you can see by the equation in the
pre-lab discussion this reaction should produce Ca(OH)2 - calcium
hydroxide.)

Repeat step 1, using a small strip of magnesium ribbon in place of
the calcium. If no visible reaction occurs, heat the water to boiling,

using a test tube holder to hold the tube over the burner ﬂame.

92

5. Once the water is boiling, stand the tube in the rack, and collect the
gas in an inverted test tube and test for hydrogen gas as in steps 1
& 2.

6. Test using phenolphthalein.

Part II

8. Obtain small (1-2 ml) samples of calcium hydroxide, magnesium
hydroxide, and barium hydroxide. Using forceps, dip a small piece
of pH Hydrion paper into a sample and notice its color change. By
comparing the color of the paper to the chart on the side of the vial
you can get a rough idea of the pH of the solution. Record the pH of '
each solution.

Part III

9. Obtain 1-gram samples of magnesium sulfate, calcium sulfate, and
barium sulfate. Put each sample into its own clean, dry test tube.

10. Add 5 mls of water to each and using your stirring rod attempt to
dissolve the solid. In the data table classify these compounds as
being soluble, slightly soluble, or insoluble.

Part IV

11. Obtain 5 ml samples of magnesium chloride, calcium chloride, and
barium chloride. Be sure to put each in its own dean, dry test tube.

12. Add about 1 ml of sodium carbonate solution to each solution and
in your data table indicate whether precipitates form or not.

Observations and Data: Please use a table similar to Table 5.

93

Table 5 - Data Table for the Alkaline Earth Metal Lab

 

Part I

 

Hydrogen Produced? Hydroxide Produced?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calcium + HOH Yes No Yes No
Hydrogen Produced? Hydroxide Produced?
Magnesium + HOH Yes No Yes No
Part II
agnesium Hydroxidel pH =
calcium Hydroxide pH =
barium Hydroxide pH =
Part III
magnesium Sulfate Soluble Slightly Soluble Insoluble
calcium Sulfate Soluble Slightly Soluble Insoluble
barium Sulfate Soluble Slightly Soluble Insoluble
Part IV
MgCl2+ Na2C03 Precipitate No Precipitate
CaCl2 + Na2C03 Precipitate No Precipitate
BaCI2 + Na2003 Precipitate No Precipitate

 

 

 

 

Calculations, Results, & Questions
1. The gas tests and pH tests you performed in this lab indicate that

when you add an Alkaline metal to water you usually produce what

two products?

2. How does the reactivity of Group 2A elements vary as you go down
the group?

3. How does the reactivity of an Alkaline Earth Metal compare with

that of an Alkali Metal in the same period?
4. Why does the metallic character of the Alkaline Earth Metals
increase as you go down the group?
Conclusion:
Write a statement that reﬂects what you have leamed about the Alkaline
Earth Metals and general trends in reactivity that occur as you go down a
metal family of the periodic table.
Reﬂection:
Write a sentence about what you learned or will remember from this

experiment.

95

Appendix D
Lab Assessment Strategies Used During Labs

Part 1 - PreLab for the Copper Formula Lab

Pre-lab Discussion:

All compounds have a deﬁnite composition in terms of the relative masses of the

elements and the number of atoms. However, the same elements may unite in

different ratios. Compounds often can be identified by the relative amount of a

particular element they contain. For example, by knowing the amount of copper

that can be removed from a copper compound, the formula of the compound can
be selected from a number of possible choices.

Purpose of the Investigation:

To experimentally determine the percent copper in a compound and to select the

formula of that copper-containing compound from a list of possible formulas.

Procedure: Day One Record all measurements in the data table.

1. Determine the mass of a 250 ml beaker.

2. (Caution: The copper-containing compound that you will use is toxic. If any
gets on your skin, wash the area with water.) Use a small plastic spoon to add
approximately two grams of the copper-containing compound to the beaker.
Determine the mass of the beaker and contents.

3. Add 75 ml of distilled water to the beaker. Stir with a glass stirring rod to
dissolve the salt. Note the results.

4. Determine the combined mass of a piece of ﬁlter paper and a watch glass.

5. Gently heat the solution to 40°C or 50°C with either a burner or a hot plate.

96

6. Remove the beaker from the heat source.

7. (Caution: The following reaction is highly exothermic and a gas is evolved.)
Place the ends of two 2 cm x 7 cm strips of aluminum into the solution. Stir
with onevof the strips.

8. Periodically scrape the copper off the strips of aluminum with a rubber
policeman.

9. When the solution’s blue color disappears, and the reaction stops (in about 10
min.), rinse any adhering solid off the metal strips and the rubber policeman
into the beaker with a few milliliters of distilled water. Remove the aluminum
strips.

10. Using the ﬁlter paper from Step 4, ﬁlter the solution. Use the rubber
policeman to transfer the entire solid from the beaker to the ﬁlter paper. Use
the ﬁltrate to rinse the beaker.

11.Dispose of the ﬁltrate as instructed by your teacher.

12. Rinse the residue on the ﬁlter paper with several 15-ml portions of WARM
(about 50°C) distilled water. Place the ﬁlter paper with collected residue on
the pre-weighed watch glass. Open the ﬁlter paper to facilitate drying. Place it
in the area designated by your teacher until the next day.

13. Wash the aluminum strips and return them as instructed by your teacher.

Day Two

14.Afler the ﬁlter paper and contents have dried, determine the combined mass
of the ﬁlter paper, watch glass, and contents (copper). Dispose of the ﬁlter

paper as directed by your teacher.

97

Observations and Data:

Table 6 — Data Table for the Copper Formula Lab

 

Data

Mass

 

1. Empty beaker

 

2. Beaker + copper containing salt

 

3. Filter paper + watch glass

 

4. Filter paper + watch glass + dry copper

 

 

 

Calculations, Results, & Questions

Table 7 - Calculations Table for the Copper Formula Lab

 

Calculations

 

1. Mass of original copper containing salt

 

2. Mass of dry copper produced

 

3. Percent by mass of Copper in the salt

 

4. Determine the percent by mass in CuCl202H2O

 

5. Determine the percent by mass in CuCI-2H2O

 

6. Determine the percent by mass in CuCl2-H2O

 

7. Which of these compounds did you have?

 

9. What is your percent error?

 

 

 

98

 

 

5.

. Explain whether your calculated percent copper would have been higher or

lower if the ﬁlter paper had not completely dried.

If a blue color appears on the ﬁlter paper with the recovered copper, what
would this imply?

Create a chart that lists other possible sources of error and whether each
error would cause a higher or lower result.

Why would it be considered a poor laboratory technique for a student to use
an aluminum scoop to measure out 5.00 g of CuCl202H2O?

Why is it doubtful that the reddish-brown product could be rust?

Conclusion:

What did you learn about determining the percent composition of a compound?

Reﬂection:

Complete one of the following stems:

One thing I learned that I did not know before is . . .
One thing that really surprised me is . . .

One thing that I will remember ﬁve years from now is . . .

99

Appendix D
Lab Assessment Strategies Used During Labs

Part 2 - Copper Formula Lab Performance Checklist

Table 8 - Performance Checklist for the Copper Formula Lab

 

Item Students

 

1 2 3 4 5

 

Correct use
Of balance

 

Filter
Technique

 

Cleanup
Day 1

 

Correct storage
Of ﬁltrate for day 2

 

Correct disposal
Of copper day 2

 

Completed
Calculation

 

 

Student determination of
Percent copper by mass

 

 

 

 

 

 

100

 

 

Appendix D
Lab Assessment Strategies Used During Labs

Part 3 - Copper Formula Interview Sheet

. When would a scientist need to determine the percent composition of a

substance?

. What do you like best about lab activities?

. What is the hardest part of this lab?

. What would you do differently if you were to do a similar lab in the future?

. How do you think you could improve your results in this lab?

. Why did this lab require two days?

. What did you learn from this lab?

101

Appendix D
Lab Assessment Strategies Used During Labs

Part 4 - Copper Formula Lab Peer Assessment Sheet

Table 9 - Peer Assessment Sheet for the Copper Formula Lab

 

Peer Assessment Sheet For the Copper Formula Lab
(scores recorded as percentages)

Student: Student:

 

Collecting l Returning Materials

 

Data Collection

 

Calculations and Analysis

 

Cleanup

 

 

 

Total Percent Contribution

 

 

Comments:

 

102

 

Appendix E

Lab Assessment Strategies Used After Labs

Part 1 - The Density of Sand Performance Task

Assignment: Design and perform an experiment that will determine the density
of sand. Write a formal laboratory report detailing your procedure, data, and
conclusions.

Background: The density of an object is equal to the object’s mass divided by its
volume. Density is expressed in units such as grams per cubic centimeter. In the
laboratory, mass is generally measured on a balance. Volume, however, can be
measured in several different ways. The nature of the objects and ways in which
their volumes are deﬁned may call for different methods of making the
measurement. The volumes of objects having regular geometric Shapes, such as
spheres, cylinders, and cubes, can be found by ﬁrst measuring the required
dimensions and then using these numbers in the formulas for their volumes. If a
sample has an irregular shape, then other, less direct methods must be used to
determine the object’s volume.

If a sample is composed of particles, as in the case of a pile of sand, one
must ﬁrst consider that the sand particles do not pack perfectly tightly, and that
the air between the particles is taking up space. If a scientist wishes to determine
the density of a sample made up of small particles, he or she is generally
interested in the volume of the particles themselves, and not the volume of the
particles plus the air between the particles. An experimental method must then

be devised to permit this determination to be made.

103

Purpose of the Investigation: To determine the denSity of a sample of sand
with air around the sand granules and then the density of the sand alone.
Procedure: Devise and write up an experimental procedure that will accomplish
the purpose of this investigation. Get your teacher’s approval of your plan before
you begin any lab work.
Data: Any date you collect during this lab Should be recorded in an appropriate
table format
Calculations 8. Results: Show your density calculations with and without air.
Conclusion: Write a summary statement of what you determined in this lab.
Reﬂection: Complete one of the following stems:

- One thing I learned that I did not know before is . . .

- One thing that really surprised me is . . .

- One thing that I will remember ﬁve years from now is . . .

104

Appendix E
Lab Assessment Strategies Used After Labs

Part 2 — Acid / Base Performance Task

 

 

Acid I Base Performance Task

You will be given four unlabeled solutions. Your task is to identify the four
solutions.
The acids could be: 1 M HCI or 0.5 M HCI or 0.1 M HCI
(phenolphthalein has been added to the acids)
The bases could be: 1 M NaOH or 0.1 M NaOH
You should devise and implement a procedure that will allow you to
experimentally determine which solution is in each container. Report your

results in the following table:

 

Solution Set Acid or Base Molan'ty

 

 

Solution A

 

Solution B

 

Solution C

 

Solution D

 

 

 

 

 

 

Figure 3 - Acid l Base Performance Task

105

 

Appendix E
Lab Assessment Strategies Used After Labs

Part 3 — Silane Teacher Demonstration Lab Assessment

Watch the demonstrations and answer the associated questions. The following

list of chemicals and compounds are involved in the reactions that you will see.

Mg - magnesium MgCI2 - magnesium chloride
Si02 - silicon dioxide (sand) SiH4 - silane

Mgzsi - magnesium silicide O2 - oxygen

MgO - magnesium oxide H2O - water

HCI - hydrochloric acid

Chemical Equations Lab Assessment Questions
In the ﬁrst reaction Magnesium and sand are reacted to form Magnesium
silicide and Magnesium oxide. What are the chemical formulas for the two
reactants in this reaction?

1. 2.

 

What are the chemical formulas for the two products in this reaction?

3. 4.

 

5. What Law must be obeyed when balancing equations?

 

6. Balance the following equation by putting the right coefﬁcients on the
blanks provided. NOTE - you may leave the blanks empty to indicate a

coefﬁcient of one.

106

Mg + SiO2 -) Mgzsi + MgO

 

7. This reaction releases a lot of energy and would therefore be classiﬁed as

what kind of reaction?

 

8. If you include the symbol Ear‘ to represent the energy given off in this

equation, on which side of the equation should you put this symbol?

 

9. We had to add energy to start this reaction. This minimum necessary

energy needed to start a reaction is called what?

 

10. The next reaction occurred when we dumped the Magnesium silicide into
Hydrochloric acid. Balance the following equation by putting the right
coefﬁcients on the blanks provided. NOTE - you may leave the blanks
empty to indicate a coefﬁcient of one.

__ Mg2Si +__ HCI -) __MgCl2 +__SIH4

11. What type of reaction is this?

 

12. The last reaction immediately followed the previous one spontaneously.
Balance the following equation by putting the right coefﬁcients on the
blanks provided. NOTE - you may leave the blanks empty to indicate a
coefﬁcient of one.

_SIH4 + _02 -> _SiO2 + __H2O
What do the following symbols mean when they are listed in a chemical
equaﬁon?

13. (9) 14. (s) 15. (aq)

 

107

Important Safety Guidelines for the Silane Teacher Demonstration

This information should be carefully read and adhered to by teachers
intending to perform the Silane Teacher Demonstration. Appropriate safety
equipment and procedures must be used at all times.

Silanes are very reactive gases, unstable in air. A mixture of Silanes is
made by reacting magnesium silicide with dilute hydrochloric acid. Making
magnesium silicide is, itself, somewhat counterintuitive, because not often do we
consider silica (i.e. send) as very reactive. However a reaction does occur when
it is heated with magnesium, a very strong reducing agent.

4Mg(s) + SiO2(s) --> Mg2Si(s) + 2MgO(s)

Mix together approximately 3.5 grams of magnesium (40 mesh - do not
use powder!) and 3 grams of clean sand. This mixture should then be put into an
8-inch test tube and clamped on a ring stand. The mixture should be spread out
along the tube. Use a safety shield between the audience and the test tube.
Carefully heat the mixture strongly until it begins to glow, and continues to glow
by itself. Allow the test tube to cool slightly and then cork the contents.
CAUTION - on several occasions I have had the test tube crack as it cools
because the reaction weakens the glass tube.

MAKE CERTAIN EVERYTHING YOU USE IS VERY DRY - THE
PRESENCE OF WATER INCREASES THE RISK OF AN EXPLOSIONIII

Use a previously prepared and cooled test tube for the next portion of the

demonstration. Break loose the cooled contents of the test tube into an

108

evaporating dish and grind up slightly with a pestle. Then sprinkle this ground up
mixture into a wide glass dish of 1 M HCI.
Mg2Si + 4 HCI --> 2MgCl2(aq) + SiH4(g)
SiH4lgl + 202(9) -> SiOzls) + 2H20
This last step is best observed in a darkened room. Silanes react
spontaneously with air and so as soon as they bubble to the surface they ignite.
Silanes are silicon-hydrogen analogs of hydrocarbons. While the hydrocarbons

are good fuels, Silanes are very unstable under similar conditions.

109

Appendix E
Lab Assessment Strategies Used After Labs

Part 4 - Copper Formula Teacher Demonstration

Table 10 - Data Table for the Copper Formula Teacher Demonstration

 

Calculations

 

1. Mass of original iron containing salt

 

2. Mass of dry iron produced

 

3. Percent by mass of iron in the salt

 

Accepted percent by mass of iron in the salt 20.6%

 

 

 

 

4. What is your percent error?

 

110

Appendix E
Lab Assessment Strategies Used After Labs

Part 5 — Written Assessment Sample
1. An investigation was completed to determine the percent of oxygen in a lead

oxide compound. The mass of the test tube was 18.68 g; the mass of the test
tube plus compound was 21.54 9. After the test tube was heated and the
oxygen gas driven off, lead remained in the test tube. The mass of the test
tube and the lead was 21.03 g.

A Prepare a data table that summarizes this experimental data.

8. Determine the percent of lead in this compound.

C. Determine the percent error if the accepted value of lead in this

compound is 86.6%.

2. Identify by names and formulas the reactants and products in question 1.

3. What part of the lab is most prone to student errors and defend your choice.
A Inaccurate use of the laboratory balance.
8. Improper heating and cooling of the reactants.
C. Incorrect ﬁltering technique.
D. Leaving the aluminum strips in the solution too long.

4. In a laboratory investigation to determine the percent zinc in a salt, students
calculated these values: Student A, 37.5%; Student 8, 41.3%; Student C,
30.9%. The accepted value was 37.6%. Describe the kind of errors that might

explain each student’s results.

111

5. A reagent bottle of copper (ll) chloride dihydrate was found to have reddish-

brown particles in it. Describe a student error that might have caused this.

6. If all the aluminum chloride were not removed during the washing, would this

increase or decrease the experimentally determined percent copper value?
7. Explain why copper (ll) chloride is not transported in metal containers.

8. The values in the right column were obtained from six different attempts to
determine the percent of copper in a copper compound using a laboratory
procedure identical to the one used in the Copper Formula lab. The accepted
value is 35.0%. Match the sample letter(s) to the statements in the left column

keeping in mind that each statement may describe more than one result.

1. There is a percent error of 14.3%. 33.5%

2. This could be a value if the copper had not completely A. 40.0%
dried. B. 35.0%

3. This could be a value if all the aluminum chloride had C. 30.0%
not been removed. D. 35.3%

4. If some of the copper remained in the beaker, this E. 38.3%

could have been a value.

112

Appendix E
Lab Assessment Strategies Used After Labs

Part 6 - Conceptualization Activity Example 1

I asked the students to watch as I took a beaker of 0.1M silver nitrate and

immersed a bent cone of copper wire into the solution. The students were

encouraged to notice the silver crystals that started to grow on the copper wire.

They were then asked to answer the following questions:

1. What is happening around the wire?

2. Why is the solution turning blue?

3. What is happening to the Silver in the solution?

4. Why does this reaction occur?

5. What role do electrons have in this reaction?

113

Appendix E

Lab Assessment Strategies Used After Labs

Part 7 - Conceptualization Activity Example #2

Part A
Use an appropriately connected Crooke’s Cathode Ray Tube and a
magnet to alter the course of a beam of light within the tube. Then answer
the following questions:
1. How is the beam of light within the tube created?
2. What does the magnet’s ability to deﬂect the beam of light suggest

about this light?

3. What does this deﬂecting beam of light tell us about the atom?

Part B
Use a straighten paperclip to probe the inside of a ball of clay. Attempt to
determine the shape of the object embedded within the clay without
opening it up. Then answer the following questions:
4. How is this similar to Rutherford’s Gold Foil Experiment?
5. What conclusions about the atom did Rutherford draw from his Gold

Foil Experiment?

Part C
.Use a spectroscope, the emission tubes, and a power supply to observe
the different colors of light given off by different gases when they are
electrically stimulated. Then answer the following questions:

6. Explain how these gases emit light:

114

. Why do the gases emit unique bright-line spectrums rather than
continuous spectrums?
. What do these bright-line spectrums suggest about the structure of

atoms?

115

Appendix F
Written Exams and Lab Practicals

Part 1 -- Semester Exam — Written Section

Short Answer:

1.

2
3.
4

What is the octet rule?

. Contrast ionic and covalent bonding:

List two effects of Hydrogen bonding:

. Explain why metals have their characteristic properties of conductivity,

malleability, and hardness.
Draw the electron dot diagrams for the following molecules:
HCN OF2
What factors affect solubility of a solute in a solvent?
Name two effects that the presence of a solute has on the physical properties
of the solvent:
What factors affect the reaction rate?
What is enthalpy? What usually happens to enthalpy in spontaneous

reactions?

10. What is entropy? What usually happens to the entropy in spontaneous

reactions?

116

Multiple Guess Questions:

11.Carefully examine a solubility table and then choose which of the following
descriptions applies to a solution that has 55 g of solute dissolved in 100 g of
water at 40°C.
A) a supersaturated solution of KNO;
8) an unsaturated solution of KCIOa.
C) a saturated solution of NH3.
D) a supersaturated solution of NH4CI.
E) a supersaturated solution of NaNOa.
Explain why you chose the answer you did:
12 If 100 g of a solution of KN03 contains 55 g of solute at 40°C, which of the
following will cause it to become a saturated solution?
A) adding 5 g of KNOa.
8) adding a single crystal of KNOa.
C) raising the temperature to 65°C.
D) lowering the temperature to 34°C.
E) adding 100 g of solvent.
How can you determine the answer by looking at a solubility table?
13. The average increase, per degree Celsius, of solubility of NaNOa between
30°C and 80°C is
A) 96 91°C. 0) 50 91°C.
B) 10 91°C. E) 146 91°C.
C) 1 91°C. F) 176 91°C

117

14. How many grams of NH3 can be dissolved in 1 kg of water at 70°C?

A) 7109 D)10g
B) 1809 E) 7.19
C) 189 F) 1.79

15.A solution contains 80 g of KN03 dissolved in 100 g of water at 70°C. Which
of the following will cause the solution to become saturated?
A) heating the solution to 137°C C) adding 23 g of solvent
8) adding 55 g of KNOB D) stirring the solution
C)cooling the solution to 420C
Explain why you chose the answer you did:
Relational-Analysis Questions:
For each of these questions there is an assertion (a statement) followed by the
word BECAUSE, then a reason. Following the question are ﬁve letters that
represent the following conclusions.
A both the assertion and the reason are true, and the reason explains the
assertion.
8. both the assertion and the reason are true, but the reason doesn't explain
this assertion.
C. the assertion is true, but the reason is false.
D. the assertion is false, but the reason is true.
E. both the assertion and the reason are false.
You should circle the letter corresponding to the conclusion you deem most

appropriate for each assertion-reason pair.

118

16.

17.

18.

19.

Assertion
Neon and Argon do not BECAUSE
react chemically.

(A) (B) (C)

Energy is released during BECAUSE

endothermic reactions.

(A) (B) (C)

A blue Copper Nitrate BECAUSE
solution can be heterogeneous

(A) ( B) (C)

A solution that contains BECAUSE
1 mole of solute in 500 cm3

of solution is 0.5 molar.

(A) (B) (C)

119

Reason
their atoms each have an octet

of electrons.

(D) (E)

in such reactions the products
contain more chemical energy

than do the reactants.

(D) (E)

Copper is a transition element.

(D) (E)

molarity is a measure of moles of

solute per dm3 of solution.

(0) (E)

Classiﬁcation Questions:
Each of these questions are followed by three short statements. Following the
statements are five letters that represent the following conclusions.

A All three statements are correct.

B. Only statements I and II are correct.

C. Only statements II and III are correct.

D. Only statement I is correct.

E. Only statement III is correct.
You should circle the letter corresponding to the conclusion you deem most
appropriate for each question and statement set.

20. Which of the following contain 10 electrons in their kernels?

I. F ll. Na’ Ill. AI
(A) (B) (C) (D) (E)
21. Metals
I. tend to gain electrons in reactions.
II. are always magnetic.
III. are malleable.
(A) (B) (C) (D) (E)

22. In order to make a 1.5 molar solution more concentrated, one can
I. raise the temperature.
II. evaporate some solvent.

Ill. add additional solute.

22. (A) (B) (C) (D) (E)

120

Appendix F

Written Exams and Lab Practicals

Part 2 - 1St Semester Exam — Lab Practical
Teacher Notes:

The students will have the entire exam period to complete eleven tasks
that review information, calculations, and procedures from the 1" semester of this
course. These tasks are not about memorization but about actually doing the
procedures and chemistry that have been studied. Consequently, the students
are encouraged to use notes, books, and other resources found in the
classroom.

The time requirements of the different tasks and the desire to more
accurately reﬂect the workplace require that the students work in groups to
produce a single test-document that determines their grade. Effective time-
management and cooperation among the group-members can signiﬁcantly
increase the amount of work that they can successfully accomplish.

The students are grouped homogeneously, with usually three other
members of the class that have demonstrated similar academic performance for
the semester. They do not necessarily compete with all the other members of
their class, but rather are graded amongst their peers as determined by semester
academic performance. The exams are graded and the scores for each level are
plotted on a graph. This graph allows me to apply a best ﬁt line to the data from
all groups. The intersection of this line with each tier is used as the denominator

when dividing the raw scores for each group in that tier. This determines the

121

perfect score for that level. This process results in an appropriate goal for each

level with higher expectations for the advanced groups. It makes a perfect 100%

possible for any group regardless of past academic performance. It also

eliminates the possibility of an unusually high score in a lower group artiﬁcially

inﬂating the goal for an entire tier.

Materials needed for each lab station during the 1‘ semester lab practical

4-beam balance

1 meter stick

1 stop watch

1 piece of paper

1 thermometer

cotton swabs

1 empty baggie

wooden splints

4 sealed Erlenmeyer ﬂasks

4 labeled ﬂame test solutions

1 unknown ﬂame test solution

122

1 small metal cube

sodium bicarbonate

copper oxide

zinc

.3 M HCI

3 M HCI

marble pieces

1 baggie of silicon dioxide

Flask with grams of HCI marked

4 sealed graduated cylinders with

liquids of varying density

1“ Semester Laboratory PractiCaI
Lab Table (- (This will be assigned by your teacher.)

Tier fl (— (This will be assigned by your teacher.)

All of the substances and equipment used to complete the following tasks can be
found at your lab station. As a group you should complete the following eleven
chemistry tasks. Remember to record all of your group’s answers on ONE
MASTER TEST - this will be the only exam paper that will be graded when
determining your entire group’s grade. Due to time and equipment restraints it is
in your own best interests to divide yourselves up so that you are completing
several tasks at the same time. A little planning, and effectively using both the
time you are given and all the members of your group, will go a long way towards

improving your score on this exam.

Task 1 Metrics 8. Scientiﬁc Notation
Determine the area of one of the side laboratory tables in square
kilometers being sure to use scientiﬁc notation and the correct number of

signiﬁcant ﬁgures.

Area of desktop in square kilometers:

 

123

Task 2 Dimensional Analysis
For this task, you will need a stop-watch, meter stick, and a piece of
paper. Make a paper airplane and when you are ready, throw it being
careful to measure both the distance in centimeters and the time in
hundredths of a second that the airplane ﬂies. Compute its speed in
meters per second. Convert this speed to miles per hour.

Distance in centimeters:

 

Time in hundredths:

 

Speed in meters per second:

 

Speed in miles per hour:

 

Task 3 - Density
Examine the four sealed graduated cylinders at your table. These four
liquids are in sealed graduated cylinders (please assume the cylinders
have the exact same mass) that should not be opened. or tipped. These
liquids should be assumed to be insoluble in each other. You should
determine the density of these liquids through careful observation and
measurement. Predict what color sequence (from top to bottom) the

liquids would display if they were all poured into the same tube.

(Top) Layer #1

 

Layer #2

 

Layer #3

 

(Bottom) Layer #4

 

124

Task 4 Substances
Take a look at the substances in the four, labeled Erlenmeyer ﬂasks and
classify them as homogeneous mixtures, heterogeneous mixtures,
compounds, or elements.

Flask A:

 

Flask B:

 

Flask C:

 

Flask D:

 

Task 5 Physical 8. Chemical Changes
Complete the following directions and describe the change that occurs in
each step as being an example of a physical or chemical change.
Step 1 - Place a medium scoop of sodium bicarbonate (NaHCOa) in 30
mls of water.

Change

 

Step 2 - Use a stirring rod to agitate the contents of the beaker and
dissolve as much sodium bicarbonate (NaHCOa) as possible.

Change

 

Step 3 - Place 30 mls of .3 M hydrochloric acid (HCI) in another beaker.
When you are ready, add the contents of the acid beaker to the other
beaker and observe.

Change

 

125

Task 6 Flame Tests

Use the 5 solutions found at your lab station for this task. Use the four,
labeled test solutions and the cotton swabs to gather some preliminary
data on ﬂame tests. When you are ready, test the unknown solution and

compare it to your data to determine the ion present in the unknown.

 

 

 

 

 

 

 

 

 

 

Test Solution Color of ﬂame Ion Present
A
B
C
0
Unknown
Task 7 Moles

Use the baggie of silicon dioxide for this task. An extra empty baggie is
provided so that you can tare the baggie’s mass. Assume all baggies have
an identical mass. Please determine the following using the appropriate
units:

Percent composition of silicon dioxide:

 

The number of molecules of silicon dioxide in your baggie:

 

The number of atoms of each element in your baggie:

 

126

Task 8 Speciﬁc Heat Capacity
Use the metal cube for this task. After determining its mass, place it in
boiling water for ten minutes. Move the piece of metal to beaker of cold
water and let it sit for ten minutes. Use your data to determine the speciﬁc

heat capacity of the metal.

Type of metal:

 

Mass of metal:

 

Volume of cold water:

 

Initial temperature of cold water:

 

Final temperature of water“.

 

Temperature change of water:

 

Heat gained by the water:

 

Temperature change of metal:

 

Heat lost by the metal:

 

Speciﬁc Heat Capacity of the metal sample:

 

127

Task 9 Stoichiometry

Complete the following laboratory procedure and record the required

information below.

1.

2
3
4.
5

Balanwd equation for the reaction:

Take two pieces of Cacog and determine their combined masses exactly.

. Place 20 mls of 3M HCI in a small beaker.

. Put the marble chips in the acid and observe the reaction.

Determine what gas is produced by performing a ﬂame test.

. Write a balanced equation for this reaction keeping in mind that there are

three products: a gas, CaCl2 and water.
Determine how many dm3s of the gas is produced.
Identify the limiting agent.

Categorize this reaction.

Mass of CaCOa:

 

What gas is produced:

 

 

dm3 of the gas produced:

 

Limiting agent in the reaction:

 

Type of reaction (synthesis, analysis, etc.):

 

128

Task 10 Experimental Stoichiometry

The teacher will give you an empty flask that indicates how many grams of
Hydrochloric Acid he will give you when you are ready. You should
calculate the exact number of grams of zinc that you will need to
completely react with this amount of HCI. Write the balanced equation for
this reaction including phases and energy terms. Predict the amounts of
each product formed (in grams or volume if a product is a gas). When you
are ready, add the zinc to the ﬂask and have your teacher perform the
reaction in the fume hood. Give your teacher the ﬂask when the reaction is
completed. Your teacher will test to see if all the reactants have been
completely consumed.

Balanced equation:

 

Grams of HCI:

 

Grams of zinc:

 

Grams of zinc chloride:

 

dm3 of gas:

 

129

Task #11 Experimental Empirical Formula 8. Percent Composition
determination

Follow the procedures as outlined on the Copper Oxide Procedures Sheet to
perform this mini-lab. Record all of your data and results below:

(A) Mass of empty test tube:

 

(B) Mass of test tube and copper oxide:

 

(C) Mass of test tube and metallic copper:

 

Mass of copper oxide:

 

Mass of metallic copper".

 

Mass of oxygen:

 

Moles of metallic copper:

 

Moles of oxygen:

 

Empirical Formula of copper oxide:

 

Percent Composition of copper oxide:

 

130

Copper Oxide Procedures Sheet

Determine an Empirical Formula through the Reduction of Copper Oxide

(Instructions for Task 11 of the 1St Semester Practical Exam)

Copper oxide can be reduced to yield metallic copper with the use of ordinary

methane gas from the classroom outlet. To do this, the copper oxide is strongly

heated in an atmosphere of methane gas in a manner which permits all end
products except copper to escape the system as gases. It is a dangerous
procedure in any laboratory to allow any gas to be freely emitted into the
classroom atmosphere. In this activity, you will use an apparatus designed to use
the gas produced during the reaction process to fuel the burner ﬂame, thus
disposing of the harmful gases. The reaction can be considered as:

copper oxide (5) + methane (g) -- > copper (s) + carbon dioxide (9) + water (9)

Procedure

1. Determine the mass of the Clean, dry, empty, large test tube.

2. Place about 1.50 grams of copper oxide wire in the test tube. Determine the
mass of the copper oxide and test tube.

3. Assemble the apparatus so that the natural gas ﬁrst ﬂows into the test tube
that contains the copper oxide and then back out of the test tube and down to
the bunsen burner beneath the tube. The teacher has an apparatus correctly
assembled on the demonstration desk for you to refer to if you have any
questions. Check your apparatus to see that the gas ﬂow and ﬂame height is

adequate.

131

 

 

. Using the assembled apparatus, heat the copper oxide until it is reduced to
metallic copper. Watch carefully for gas leaks. This will take approximately 15
to 30 minutes.

. Heat the walls of the test tube to drive out any condensed water.

. Remove the burner from underneath the test tube, but allow the ﬂame to burn
for an additional 5 minutes or until the copper is cool. This step removes
harmful gases and helps cool the copper.

. Mass the test tube and metallic copper.

132

Appendix F
Written Exams and Lab Practicals

Part 3 — 2"d Semester Exam - Lab Practical
Teacher Notes:

This is a lab practical. The students have already demonstrated their
individual book-knowledge on the separate parts of the ﬁnal exam given at the
end of each marking period. In this lab practical the students will have the entire
exam period to complete approximately 12 tasks that review information,
calculations, and procedures from the 2"“ semester of this course. These tasks
are not about memorization but about actually doing the procedures and
chemistry that we have studied. Consequently, the students are encouraged to
use their notes, books, and other resources found in the classroom.

The time requirements of the different tasks and the desire to more
accurately reﬂect the workplace require that the students work in groups to
produce a single test-document that determines their grade. Effective time-
management and cooperation among the group«members can signiﬁcantly
increase the amount of work that they can successfully accomplish.

The students are grouped homogeneously, with usually three other
members of the class that have demonstrated similar academic performance for
the semester. They do not necessarily compete with all the other members of
their class, but rather are graded amongst their peers as determined by semester
academic performance. The exams are then graded and the scores for each

level are plotted on a graph. This graph allows me to apply a best ﬁt line to the

133

data from all groups. The intersection of this line with each tier is used as the
denominator when dividing the raw scores for each group in that tier. This
determines the perfect score for that level. This process results in an appropriate
goal for each level with higher expectations for the advanced groups. It makes a
perfect 100% possible for any group regardless of past academic performance. It
also eliminates the possibility of an unusually high score in a lower group

artiﬁcially inﬂating the goal for an entire tier.

List of Materials to be placed at each lab station

4 heat sensitive periodic tables paperclips

4 sheets of isomer drawing paper string

Spot test solutions index cards
Spot Test grids label tape
Organic model kits marker

Blank Paper food coloring

1 Florence ﬂask hot glove

1 thermometer soap

1-hole 8. solid stoppers for ﬂasks Alka-Seltzer

1 Erlenmeyer flask Buret with sulfuric acid solution
balloons to ﬁt Erlenmeyer flask 100 ml 6M HCI
3 ft of glass tubing 6 9 Zn

134

2nd Semester Lab Practical

Lab Table (— (This will be assigned by your teacher.)

 

Tier # (- (This will be assigned by your teacher.)

 

All of the substances and equipment used to complete the following tasks can be

found at your lab station.

Task 1: Phases of Matter
Make a working thermometer complete with an accurate temperature
scale indicating a temperature range of at least 50 degrees. Attach some
tape with your names on the thermometer and hand it in to the teacher. In
the space below, give a concise but very accurate explanation of how a

thermometer works.

Task 2: Phases of Matter
Perform the following "Double Boiler" demonstration.

1. Bring a half-filled Florence ﬂask of water to a boil.

2. Carefully remove the ﬂask from the heat source.

3. Using a solid stopper - seal the ﬂask.

4. Carefully invert the sealed ﬂask and run cool water over the
outside of the ﬂask until the water inside the ﬂask begins to boil
again.

In the space below, give a concise but very accurate explanation of how

this demonstration works.

135

 

Task 3: Electron Conﬁgurations
What is the electron conﬁguration for the Iodine ion ( l'1 )?

Task 4: The Periodic Table
The Periodic Tables found at your lab station change color with the heat
from your hand. As the paper cools, it changes back to its original color. Is
the change from the second color back to the ﬁrst color endothermic or
exothermic? Explain why in detail:

Endothermic Exothermic

 

Why:

Task 5: The Periodic Table
Using the clues given on the next two pages, ﬁll in the following diagram
with the appropriate letters of the alphabet. These letters represent the S

and P block elements of the top four rows of the periodic table.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 4 — Practical Exam Periodic Table Grid

136

Periodic Table - Task 5 continued.

The code letters A to 2 have been assigned to the ﬁrst 26 elements in the short
form periodic table. (This table omits the transition elements in period 4.) These
code letters do not represent the chemical symbols nor have the letters been
assigned in alphabetical order. Study the given clues based on experimental

data. Then place the code letters in their correct positions in Figure 4.

Clues
1. The following elements belong together in families: BJW, CFLS, DHR,
EGOX, AMU, QVY, NPZ, IKT
If this atom formed ions, the ions for H would be +4 or -4.
RT2 is the formula of an oxide.
F is a noble gas.
G is an alkali metal.
Y has 5 electrons in its outermost energy level.
8 has 2 valence shell electrons.

M has an outer electronic conﬁguration of 4s2 4p‘.

SDSPNP’S’IPP’N

N is a halogen.

10.A has the smallest atomic mass in its family.

11.P is a green gas at STP.

12. R has the lowest ﬁrst ionization energy in its family.
13.8 is more metallic than L.

14. The nucleus of C could be called an alpha particle.

137

 

Periodic Table - Task 5 continued

15.x is found in table salt.

16.2 is a liquid but N is a gas at room temperature and pressure.

17. F contains ten protons.

18. The electrons of atom V are distributed over four energy levels.
19.0 is the least metallic in its group.

20. K is more metallic than either I or T.

21 .The atomic mass of B is less than that of J but more than that of W.
22.The atomic number of l is one greater than that of Y.

23.Atoms of G are smaller than those of E.

24.The last term in H's electronic conﬁguration is 3p“.

138

Task 6:Chemical Bonding

Create and Show the teacher a demonstration of Hydrogen Bonding.

Task 7: Chemical Kinetics
Experiment with different factors that affect the rate at which Alka-Seltzer

dissolves. Describe at least two different strategies of speeding up the

 

reaction between water and Alka-Seltzer. Describe how chemical kinetics,

 

the kinetic theory of matter, and potential energy diagrams explain why
these strategies Speed up this reaction.
Stategy 1:

Explanation:

Strategy 2:

Explanation:

Task 8: Gas Laws
Using 100.0 ml of 6.00M HCI and 3.00 grams of Zinc in a Erienmeyer
ﬂask, produce and capture in a balloon some Hydrogen gas. Calculate
what volume of Hydrogen gas has been captured. Prove that you have

produced Hydrogen gas by detonating the balloon at the teacher’s desk.

Volume of Hydrogen gas:

 

139

Task 9: Organic Chemistry
Name and draw the structural formulas for all the isomers of DiChloro
Pentadiene on the back of this paper.

Task 10:Solutions
Produce a 200.0 ml sample of 2.00M NaOH Solution. You may obtain the
necessary mass of NaOH by submitting to your teacher an index card
from your lab station showing all the calculations and the actual amount of
NaOH you need. When completed with this task you must show your
solution to the teacher before attempting task 11. The teacher will check

your solution’s concentration before you begin task 11.

Task 11: Acid Base Reactions
Use your 2.00M NaOH solution produced in task 10 to determine ﬂ'le
molarity of the standard solution of the sulfuric acid solution in the buret at
your lab station.

Calculations:

Molarity of Sulfuric acid:

 

140

Task 12: Spot Test
Use the solutions listed below and the procedure from the next page to
perform the spot test. You should perform the Spot Test on the piece of
plastic found at your stations. A blank piece of paper underneath the
plastic makes it easier to observe the colors. Please be careful not to
contaminate your solutions. Identify your six solutions and record your

results here:

 

 

 

 

Reagents Reagents
Solution #1: Solution # 4:
Solution # 2: Solution # 5:
Solution # 3: Solution # 6:

 

 

Spot Test Directions
Solutions:
1M acetic acid
1M hydrochloric acid
0.2M lead acetate
0.04M mercuric chloride
0.2M potassium iodide

0.04M Silver nitrate

141

Procedure:

Identify the speciﬁc ion (and hence the solution) that is in each reagent bottle by
the pair-wise mixing of a drop from one bottle with one drop from another bottle.
By carefully mixing the solutions drop by drop and comparing the colors of the
precipitates that form with the following information you should be able to

correctly identify the solutions in each bottle.

Precipitates:
lead iodide (Pbl2) is a deep yellow precipitate.
mercuric iodide (Hgl2) is an orange-red precipitate.
lead chloride (PbCl2) is a white precipitate.
silver iodide (Agl) is a light yellow precipitate.
silver chloride (AgCI) forms a white precipitate that gradually turns violet.

acetic acid will not form a precipitate in these reactions.

142

Appendix G
Posttest, Strategy Evaluation, and Survey

Part 1 — Posttest

Please indicate how much you agree with the following statements. Base your
answers on this science course only. Record your answers by circling a number
from one to ten. Circling a one means that you strongly disagree and circling a
ten means you strongly agree.
1. Science courses should offer students lab activities.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
2. I believe that lectures and discussions teach Chemistry more effectively than
lab activities.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
3. I think science courses should offer more lab activities than they do.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
4. I think that labs are more work than they are worth.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
5. Lectures and labs in science courses are clearly connected.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
6. Science course laboratory work has increased my understanding of how
scientists actually work.
(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
7. Labs make science more relevant to my life.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)

143

8. Lab work increased my interest in science.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
9. Lab activities taught me more about science than the book or lectures did.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
10.! prefer open-ended investigative labs of my own design.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
11.Lab work improves my understanding of the material covered in lectures.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
12.! prefer traditional written tests to nontraditional tests that require me to do

something.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
13. lnfonnation from lab work should be a part of tests.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
14.I concentrate more closely on lab work if I know I am going to be tested over

the lab.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (StronglyAgree)
15. Laboratory notebooks helped me to understand the labs better.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
16. This science course offered more lab activities than most science courses.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)
17. Lab assessments are harder than traditional tests.

(Strongly Disagree) 1 2 3 4 5 6 7 8 9 10 (Strongly Agree)

144

Appendix G
Posttest, Strategy Evaluation, and Survey

Part 2 — Laboratory Assessment Strategy Evaluation

Please evaluate the laboratory assessment strategies that were used in
this course. There are three areas that I would like you to evaluate about each
strategy. First, I would like to know how effective you thought each strategy was
in terms of its ability to measure what students have learned. (This is the purpose
of laboratory assessment.) Second, I would like you to evaluate how effective
you thought each strategy was in terms of its ability to teach new material. (This
is an important side benefit of laboratory assessment.) Thirdly, I would also like
you to indicate how much you enjoyed the various strategies.

Lab notebooks:

Evaluation effectiveness: (Low) 1 2 3 4 5 6 7 8 9 10 (High)
Teaching effectiveness: (Low) 1 2 3 4 5 6 7 8 9 10 (High)
Personal enjoyment: (Low) 1 2 3 4 5 6 7 8 9 10 (High)

Performance Checklists:

Evaluation effectiveness: (Low) 1 2 3 4 5 6 7 8 9 10 (High)
Teaching effectiveness: (Low) 1 2 3 4 5 6 7 8 9 10 (High)
Personal enjoyment: (Low) 1 2 3 4 5 6 7 8 9 10 (High)

Student Interviews:

Evaluation effectiveness: (Low) 1 2 3 4 5 6 7 8 9 10 (High)
Teaching effectiveness: (Low) 1 2 3 4 5 6 7 8 9 10 (High)

Personal enjoyment: (Low) 1 2 3 4 5 6 7 8 9 10 (High)

145

Peer Assessments:
Evaluation effectiveness: (Low)
Teaching effectiveness: (Low)
Personal enjoyment: (Low)
Performance Tasks:
Evaluation effectiveness: (Low)
Teaching effectiveness: (Low)
Personal enjoyment: (Low)
Open-ended Labs:
Evaluation effectiveness: (Low)
Teaching effectiveness: (Low)
Personal enjoyment: (Low)
Teacher Demonstrations:
Evaluation effectiveness: (Low)
Teaching effectiveness: (Low)
Personal enjoyment: (Low)
Written Assessments:
Evaluation effectiveness: (Low)
Teaching effectiveness: (Low)

Personal enjoyment: (Low)

146

10
10
10

10
10
10

10
10

10

10
10
10

10
10
10

(High)
(High)
(High)

(High)
(High)
(High)

(High)
(High)
(High)

(High)
(High)
(High)

(High)
(High)
(High)

Conceptualization Activities:
Evaluation effectiveness: (Low)
Teaching effectiveness: (Low)
Personal enjoyment: (Low)

Lab Practicals:

Evaluation effectiveness: (Low)
Teaching effectiveness: (Low)

Personal enjoyment: (Low)

147

78910
78910
78910

78910
78910
78910

(High)
(High)
(High)

(High)
(High)
(High)

.‘IP’S’IPP’N

or

10.

11.

12.

13.

14.

15.

Appendix G
Posttest, Strategy Evaluation, and Survey

Part 3 — Posttest Survey Questions
Did you enjoy this science course?
00 you enjoy labs?
What is the best part about labs?
What is the worst part of labs?
Why did we perform labs in this science course?
Were the labs necessary?
What was the best part about using a lab notebook?
Why do you think the teacher required you to use a lab notebook?
Would you recommend the use of lab notebooks for future
chemistry students? Why?
Did you prefer the more structured labs or the open ended ones?
Why?
How often should students perform lab activities during a science
course?
How should teachers evaluate the Ieaming that occurs during lab
activities?
Should questions about recent labs being included on tests?
Should tests include lab activities?
How should teachers improve the connection between labs and

lectures?

148

16.

17.

18.

19.

20.

21.

How did lab activities improve your understanding of chemistry?
What teaching strategy (lectures, demos, labs, etc.) taught you the
most about chemistry? Why?

What type of information or material is most effectively evaluated
using laboratory assessment?

What was your favorite assessment strategy? Why?

Should the teacher continue to use formalized lab assessment in
the future? Why?

What did you like the most about the lab assessment procedure
used in this course?

What did you like the least about the lab assessment procedure

used in this course?

149

Appendix H
Open Ended Labs with Rubrics

Part 1 - Chemical Bonding Investigation

Objective:

Your task is to write a procedure one could follow to identify two unknown
compounds as having either ionic or covalent bonds.
Scenario:

You are given two unidentiﬁed, white, crystalline compounds. You must
devise a procedure to be used in the laboratory to classify these compounds as
having either Ionic or Covalent bonds.

Instructions:

Your procedure must be clear and detailed enough that any ﬁrst year
chemistry student would be able to follow it You must include step-by-step
instructions. You must specify amounts, proper glassware, lab techniques,
safety precautions, disposal procedures, order, observations that should be

noted, important qualities for which to watch, etc. You must also include at least

 

110. "tests" that will be used to identify the compounds.
Example:
I was asked to devise a system to identify two white materials as
either plastic or paper. Each was thin like a sheet of paper, each
had similar coloring, and the two could easily be mistaken for one

another.

150

 

Procedure: (from the example)

1.

SAFETY GLASSES SHOULD BE WORN AT ALL TIMES
DURING THIS LAB! Obtain the two samples to be tested.
Assign each a code letter.

Visually inspect the two samples carefully noting any
differences.

Record 3 observations about each in the data table: (Note: a
”slippery" surface might denote plastic and easily ripped
samples could identify paper)

Next, out each sample into fourths, keeping the two samples
separate.

Take one fourth of each sample and place it on the lab table in
front of you.

With a dropper pipet, drop distilled water (10 drops) onto each
of the samples. Record observations in the data table. (Note:
paper will traditionally absorb the water droplets but plastic will
repel the water leaving the drops intact resting on the surface of
the sample)

The wet samples may be disposed of in the trashcan.

Repeat steps 5, 6, and 7 with a different section of each sample.
Take a different fourth of each sample and perform the following

test.

151

10. With tongs hold one of the samples about 15 cm over the top of
a Bunsen burner. CAUTION: USE CARE WHEN USING
BUNSEN BURNERS. KEEP HAIR AND LOOSE CLOTHING
TIED BACK, AWAY FROM FLAMES.

11. Record observations in the data table.

12. With tongs hold the other sample about 15 cm over the top of a
Bunsen burner.

13. Record observations in the data table. (Note: The paper sample
should burn with a bright orange ﬂame leaving behind a black
residue. The plastic sample should not burn, but will melt when
held over the ﬂame. The plastic sample may be discolored
slightly by the gentle heating, leaving a brown color on the white
plastic.)

14. Repeat steps 9 through 13 with two fresh samples.

15. The bumedlmelted samples should be cooled to room
temperature and disposed of in the trash container.

16.Tally data in the data table. The data should Show consistent
trends for either plastic or paper properties. Determine which
substance is paper and which is plastic.

The data table I used for this sample investigation is included on the next
page. These instructions and the data table are provided as samples only. Your

procedure and data table should be very different from these samples.

152

 

Table 11 - Chemical Bonding Investigation Sample Data Table

 

 

Sample Sample
Code Letter A Code Letter §
Visual White, slightly shiny, White, not shiny,
Inspection not slippery Not slippery

 

Water droplets stand Water droplets stand
Water Test #1 up in little round up in little ﬂatten
bubbles bubbles

 

Same as before, water Same as before,

 

 

 

 

 

 

 

Water Test #2 drops leave no wet slight wet marks left
marks by drops
Burner Test #1 Melts quickly Chars and then burns
Sample melted then Sample burns
Burner Test #2 caught on ﬁre completely to a black
residue
Conclusion:

Since sample A demonstrated properties during these tests
consistent with those of plastic, based on this experiment, I would

conclude that Sample A is a type of plastic. Sample B’s properties

would cause this experimenter to conclude that it is a form of paper.

153

. _lL
l-IL

Chemical Bonding Lab Assessment Rubric

Detail of Instructions (How well can this procedure be followed?)

Easily — no questions at all 3 pts
Somewhat — 1 to 3 questions 2 pts
Barely - 4 to 5 questions 1 pt
Data Table
Complete, useable data table given 2 pts
Incomplete data table 1 pt
Missing data table 0 pts
Thoroughness of Tests
Two tests given to identify compounds 2 pts
Less than two tests given 0 pts
Quality of Tests #1 and #2
Test will determine bond character 2 pts 2 pts
Test will not determine bond 0 pts 0 pts
Expected outcome given for both 2 pts 2pts
Emcted outcome given for one 1 pt 1pt
No expected outcome given 0 pts Opts
Safety Precautions
Given for all necessary items 2 pts
Disposal
Given for all disposable materials 1 pt

154

Appendix H
Open Ended Labs with Rubrics

Part 2 — Eggsplosions Lab Activity

The following pages were given to the students at the beginning of the activity.

Eggsplosions
This is your opportunity to PROVE what you know about chemical

reactions, the gas laws, chemical kinetics and thermodynamics.

Your mission is to produce the most spectacular Eggsplosion in class.You
will be using hydrogen gas to make a small explosion (under your teacher’s
supervision) to blow up an empty eggshell on the center table. You should ﬁrst
examine the materials on the side shelf provided by your teacher to decide how
you are going to generate the necessary reactants for your eggsplosion. You will
be graded on both your eggsplosion and your explanation of it.

You must write out a plan for creating any and all reactants that you will be
using. You must show your teacher a speciﬁc step-by-step procedure that
includes all the applicable safety guidelines and the appropriate chemical
reactions. Only after obtaining your teacher’s written permission are you to
proceed with your experiment!

When you have obtained permission to proceed you may collect your

materials. Before you actually start generating your reactants, you should

155

carefully plan how you are going to manage the mechanics of ﬁlling your egg. On
the same paper as your teacher approved plan you should answer the following
procedural questions:

1. How are you going to ﬁll the egg?

2. What amount of which reactants are you going to ﬁll the egg with?

3. How are you going to prevent the premature loss of reactants from the

egg?

After answering these questions you should be able to ﬁll your egg.
Please mark the outside of your egg, ﬁll it according to your plan, seal it using
tape and place it in the place indicated by your teacher. When everyone is ready
we will initiate and evaluate your eggsplosions. To earn a passing grade you

must also answer the following analysis questions:

1. Why do some eggs explode immediately and others do so only after

burning a short while?

2. How does the concenﬁation of the reactants affect this reaction?

3. Why does the egg actually explode instead of just burn?

4. What should today’s activity suggest to you about the safety and

appropriate use of natural gas to heat our homes?

156

 

Suggested Format and Grading Rubric for the Eggsplosions Lab Activity

1) Procedure
This section contains the complete step-by-step directions that you plan to
follow in this experiment. You must submit this proposed procedure for
approval to your teacher BEFORE continuing to the rest of the
experiment. This section is worth up to 3 points.

2) Safety Guidelines
This section should contain a complete set of safety guidelines suitable for
this experiment. This section is worth up to 3 points.

3) Chemical Reactions
Please list the complete chemical equations for the reaction used to
generate the hydrogen gas and the reaction used to detonate the egg.
This section is worth up to 2 points.

4) Procedural Questions
Answer the three procedural questions from the introduction. This section
is worth up to 3 points.

5) Analysis Questions
The four analysis questions listed on the introduction should be answered
here. This section is worth up to 4 points.

Total Points possible = 15 points.

157

 

Appendix I

Various Lab Assessment Activities

Part 1 - Marble Challenge Graphing Assessment

Teacher notes:
This open-ended laboratory is designed for students who have just
concluded a unit on scientiﬁc measurement including the effective use of
graphing. It is designed to challenge the students to design their own
logical process for determining the average mass of some marbles sealed
in a jar. Each lab group has a different set of jars with different numbers of
marbles in them. A preliminary discussion should be held pointing out why
taking the difference in mass between two jars and dividing it by the jars’
difference in mass would not produce precise or accurate values. The
students may also need a review of some basic math associated with

graphs such as how to solve for values, slope, etc.

Student lnfonnation:

At your lab stations you have been given several sealed jars of marbles, balls,
etc. Each jar contains a number of these marbles. You should mass these jars
and by extrapolation determine the mass of a single marble. Decide what
procedure you will use before you begin experimenting. Record all pertinent data
and make a graph of your results. Be sure to answer the questions about this

activity.

158

 

Procedure: (Use this space to list a step-by-step procedure that you will use.)

1.

2.

3.

4.

5

Data: (Use this space to record your observations and measurements in a neat

data table.)

Calculations, Results, 8. Questions:

Graph: Please attach your graph paper to this sheet. Be sure to title the
graph, name and label the axis’s, and record your data
appropriately.

Slope: Determine the slope of your curve. The equation is y=mx+b, where
m is the slope and b is where your curve intercepts the y axis.

Questions:

What is the mass of a single one of your marbles? (Use your graph and

it’s slope!)

What would the total mass be for a jar containing (assume it is possible)

twentyﬁve of your marbles?

What does (or should) the Y intercept on your graph tell you?

159

Appendix I

Various Lab Assessment Activities

Part 2 - Observing a Chemical Reaction Performance Task

Teacher notes:
This Simple performance task is designed for beginning chemistry
students ﬁnishing a unit on the scientiﬁc method and introductory
laboratory skills. A preliminary discussion contrasting observations and
interpretations should be concluded before beginning this activity.
Students will also need to be aware of the difference between qualitative
and quantitative observations. Safety and the need for careful
observations should be emphasized

Student Information:

Waming - The copper compound you will be using is quite toxicl Please

handle it with care. Wear safety goggles atall times.

1. Place 3 grams of copper (ll) chloride dihydrate CuCI2-2H2O crystals in a
medium sized beaker. Describe the crystals in the data table.

2. Add 20 ml of water to another medium sized beaker and without stirring add
the crystals from the ﬁrst beaker to the beaker with the water. Record your
observations in the data table.

3. Use a stirring rod to stir the mixture until the crystals are completely
dissolved. Record the temperature of the solution along with any other

observations you can make.

160

 

4. Make a loosely crumpled ball of aluminum foil about the size of a Ping-Pong

ball and place it into the solution. Record as many observations as possible.

Table 12 - Data Table for the Observing a Chemical Reaction Task

 

Observations

 

Copper(ll) chloride

crystals

 

Copper(ll) chloride in H20

 

Dissolved copper(ll)

chloride

 

 

Copper(ll) chloride + al foil

 

 

 

Analysis

1.

Examine your observations. Cross out any that are interpretations instead
of observations. Circle any observations that are quantitative.

What advantages do observations have over interpretations?

Why do scientists prefer quantitative observations when possible?

When are interpretations useful and appropriate for scientists?

Why is it important for scientists to accurately indicate which of their

ﬁndings are observations and which are interpretations?

161

Appendix I

Various Lab Assessment Activities

Part 3 - Ziploc Changes Laboratory Assessment

Teacher notes:
In this laboratory assessment, the students demonstrate their abilities to
carefully observe m experiment and differentiate between physical and
chemical changes. The amounts of the reactants are not critical and

therefore this tends to be a very quick and easy to perform activity.

Student lnfonnation:
Wear safety goggles at all times. Report any spills to your teacher

immediately.

In this activity you will be demonstrating your ability to carefully observe a

reaction and document the physical and chemical changes that you detect.

Procedure:

1 Prepare a chart on the back of this paper with a column for physical and a
column for chemical changes.

2 To a Ziploc baggie add one small scoop of calcium chloride.

3 Now add one small scoop of sodium bicarbonate to the same baggie.

4 Carefully observe the characteristics of the mixture in your baggie so that

you will be able to notice any changes that occur.

162

 

Using a pipette, obtain a small amount (less than 2 mls) of phenol red (an
indicator that turns red in a base and yellow in an acid). When you are
ready to carefully observe all the changes that occur in the baggie, squirt
the phenol red into the baggie and seal it.

Using your senses of sight and touch, look for as many signs of physical
and chemical changes as you can observe inside the baggie and record

these on the bottom of this paper.

163

 

Appendix I

Various Lab Assessment Activities

Part 4 - Unclogging Your Pipes Laboratory Assessment

Teacher notes:
This investigation should be used very early in a chemistry course
perhaps in conjunction with a unit test over chemical and physical
properties and changes. Students should have a beginning understanding
of correct laboratory procedures and laboratory safety. Laboratory
activities such as this that investigate the chemical properties of common
household products can greatly increase the connections students see

between chemistry and the “real” world.

Student lnfonnation:
Solid drain cleaners like Drano contain sodium hydroxide pellets, aluminum
shavings, coloring material and scent It is important to remember that the
producers of this product are obviously proﬁt motivated. This means that they are
interested in producing a cleaner that:

1. Works.

2. Will be popular with the consumer.

3. Sells with an acceptable proﬁt margin.
You should keep in mind that the manufacturers would probably arrange these
criteria in the reverse order. By careful analysis we can discover the purpose for

each of the ingredients in the drain cleaner.

164

“f.

Warning - The drain-cleaning compound you will be using is quite toxic
and caustic! Please handle it with care. Wear safety goggles at all times. Do
not let the compound or any liquid containing the compound to come in

contact with your skin. Report any spills to your teacher immediately.

Equipment:
1 - 50 ml beaker 1 - 150 ml beaker 1 thermometer Safety glasses
Procedure:
1. Place a small sample (approx. 1 teaspoon) of Solid Drain Cleaner in your
50 ml beaker. Examine it closely but DO NOT TOUCH it.
2. Place 50 mls of water in your 150 ml beaker. Determine its temperature.
3. Carefully pow the Drain Cleaner into the beaker of water and watch
closely what happens. Record the temperature of the reaction.
4. Answer the questions on the back of this paper.

5. Rinse everything carefully with water when ﬁnished.

Analysis:

1. Sodium hydroxide (the little pellets) immediately began to dissolve in the
water in your beaker. This dissolution of sodium hydroxide is what type of
change? (physical or chemical)

2. Was this dissolution of sodium hydroxide an endothennic or exothermic

reaction?

165

 

3. The dissolved sodium hydroxide is a caustic base. How does this help clean
your drain?

4. Why did the producer include small shavings of aluminum?

5. The energy released by this dissolution of sodium hydroxide was sufficient to

cause the aluminum shavings to begin to react. What name could be applied

to this energy?

Did the aluminum undergo a physical or chemical change?

Was the change that the aluminum underwent endothermic or exothermic?

Where was the hottest part of the reaction in your beaker and how hot was it?

SDPONP’

How could this temperature increase help break up a clog in a pipe?

10. How could the bubbling help break up the clog?

11.The gas released was the result of the breaking apart of the water molecule.
It is explosive! What gas is it?

12.Why is it important to run a lot of water down your pipes after the clog has
been broken up?

13. Why did the producer include a scent and coloring agent?

14. Why should a person with aluminum plumbing NEVER use Drano?

15. What should you do if you ever get drain cleaner splashed on you?

166

Appendix I

Various Lab Assessment Activities

Part 5 - Liquid Nitrogen Conceptualization Activity

Teacher notes:
Before beginning this activity the teacher should share and demonstrate
the following lnfonnation: Rubber balls bounce because they store their
kinetic energy by deforming on a hard surface. Steel balls also bounce
(but not as well) because they deform the surface they bounce on.
This variation of the standard liquid nitrogen demonstrations can be used
to assess the students’ understanding of temperature and the IGnetic
Theory of Matter. This activity is designed to be demonstrated by the
teacher using students to help collect and interpret the data. The graph
will show that the frozen ball bounces very well in a manner similar to a
steel ball. As the ball warms up, it will lose its bounciness. Then, as the
ball returns to room temperature, it will regain its bounce as it becomes
sufﬁciently softer that the surface and begins to demonstrate its typical
elasticity. Safety around limid nitrogen and the need for careful
observations should be emphasized.

Student lnfonnation:

The teacher will cool a bouncy ball (superball) in liquid nitrogen as the

demonstration begins. Once the ball has cooled for ten minutes, two students will

be used to collect lnfonnation on how the temperature of the ball affects its ability

to bounce. The students will drop the ball once every ﬁve seconds from a height

167

 

of one meter on to a hard surface and measure how high it bounces on its ﬁrst
bounce. All other students should record this data by plotting the information on a
graph. This graph should have the height in centimeters on the vertical axis and
the number of the drop on the horizontal axis. The ball will be dropped sixty times
in ﬁve minutes.

Answer the following questions before the demonstration begins:
1. What is liquid nitrogen?

2. When we throw a “Super Ball” into the liquid nitrogen - it bubbles. What

are the bubbles?

3. What is happening to the molecules of the liquid nitrogen as it bubbles?

4. Why does the bubbling eventually stop?

5. What is happening to the molecules in the ball as it sits in the liquid?

6. What conservation law is being obeyed here?

7. How do you think this will affect the ball’s ability to bounce?

8. As the ball warms up, will the bounce improve back to its original height?

168

 

The demonstration should be performed at this point. The students should
then answer the following questions:

9. What is similar about how rubber balls and steel balls bounce?

10. How can this explain what happened to the “Super Ball” after it was

immersed in liquid nitrogen?

11. What is the energy being used for during that stage when the “Super Ball“

doesn’t act like either a mbber ball or a steel ball?

12. What did you learn from this experiment?

169

Appendix I
Various Lab Assessment Activities

Part 6 - Elements, Mixtures, and Compounds Separation Activity

Teacher notes:

This activity is designed to evaluate the student’s understanding of basic

laboratory procedures and how matter is organized. It requires the student
to design their own laboratory process for separating the materials in a
ﬂask prepared for them by the teacher. Typical ﬂasks might contain room
air, Italian salad dressing, sand and salt, or alcohol and water. I would
suggest having the students outline a process for at least three different

ﬂasks.

Student lnfonnation:

The ﬂask on your desk contains a mixture of materials. You are to design a

laboratory process that will separate the mixture into its basic components.

1. Please describe the contents of your ﬂaslc

2. Classify the contents of the ﬂask as one of the following: solid, liquid, or gas.

3. Classify the contents of the ﬂask as an element, compound, or mixture (be

sure to specify heterogeneous or homogenous mixture).

170

' f

4. You should now propose a scheme or process that could be used to separate
the contents of the ﬂask. On the bottom of this sheet, please describe this
process as if it were to be followed by someone other than a member of your
group. You should use pictures or diagrams to help others visualize this
process. Remember to use complete sentences, detailed drawings, and don't

skip any steps.

171

Appendix I

 

Various Lab Assessment Activities

Part 7 — How Big is a Mole Laboratory Assessment Activity
Teacher notes:

This activity can be used to determine how well a student understands the

mole concept and associated calculations.

Student lnfonnation:
You are to determine the number of molecules in a mouthful of water. Fill a cup
with water and determine the mass to the thousandth of a gram. Drink one

mouthful of water. Reweigh the cup and remaining water. Calculate the number of

 

 

 

molecules that you drank

Observations:

A Mass of cup and water initially = 9

8. Mass of cup and water after drinking = Q

C. Mass of water swallowed (A-B) = 9

D. Molar mass of water = glmol

 

(How much does a mole of water weigh?)

172

E. Moles of water swallowed (CID) = mol

 

F. Number of molecules per mole = molecules/moi
(Avogadro would know this one!)
G. Number of molecules swallowed = molecules

 

(E x F please answer in ScientiﬁcNotation)

H. Number of mobcules swallowed NOT in scientiﬁc notation

 

= molecules
Analysis
1. Were you surprised at how many molecules of water you drink in every
mouthful?

2. How many molecules of water are in an entire bottle (5409) of bottled

water?

173

Appendix I

Various Lab Assessment Activities

Part 8 - Corrosion of Iron Laboratory Assessment
Teacher notes:
Students enjoy this activity and Ieam an important rule of ﬁre safety during
this mini-lab. To prevent accidental ﬁres, do not let the students pick up
batteries and steel wool at the same time. Do not dispense the batteries

and steel wool from the same desk.

Student Information:

Be careful to keep the batteries and the steel wool away from each other until you
are ready to begin.

Materials
evaporating dish balance steel wool 9-volt battery
Procedure:
1. Mass your empty evaporating dish.
Obtain a small piece of steel wool and spread it apart.

Re-mass the evaporating dish after you have placed the steel wool in it.

P99!”

Touch the 9-volt battery terminals to the steel wool. Observe what happens.
Repeat this step until no further reaction takes place.
5. Re-mass the evaporating dish with the burned steel wool.

6. Record your observations and calculations on the back of this paper.

174

Data

Mass of empty evaporating dish

 

Mass of dish + unburned steel wool

 

Mass of unburned steel wool

 

Mass of dish + burned steel wool

 

Mass of bumed steel wool

 

3“!“909’?

(000000

Change in mass of steel wool

 

Analysis

1. Why shouldn’t you keep steel wool and batteries together?

2. How did the mass of the steel wool change as a result of buming?

3. What is the formula for the iron oxide made in this experiment if the iron is

Fe+3 and the oxygen is 0'2?

4. Why did the steel wool gain mass?

5. Was this a physical or chemical change?

6. This is the same reaction'that occurs when iron rusts. The only difference is

the speed of the reaction. How can the rusting (corrosion) of iron be

prevented?

175

Appendix I

Various Lab Assessment Activities

Part 9 — Hydrogen Bonding Laboratory Assessment

Teacher notes:
This activity is a set of three mini-demonstrations performed by the
teacher and students and a series of questions that are all designed to

evaluate a student's understanding of hyrtogen bonding.

Student lnfonnation:

Watch the three demonstrations and using your knowledge of hydrogen bonding,
answer the questions on this sheet

The Alcohol Race

Your teacher will drop one drop of each of the following liquids on a piece of

slate. You should record the time it takes for the drop of each compound to

 

 

 

evaporate.
Compound Molecular Mass Time to Evaporate
butanol 74.10 glmol seconds
propanol 60.08 glmol seconds
ethanol 46.06 glmol seconds
methanol 32.04 glmol seconds

 

Predict the time it will take for water to evaporate.
Compound Molecular Mass Predicted Time to Evaporate

water 18.02 glmol seconds

176

 

Now record the actual time it takes for water to evaporate:
Actual seconds
1. Account for differences in your predicted time and the actual time it took for

water to evaporate.

Floating Metal

Fill a small bearer almost completely with water. Obtain a sample of straight
pins from the front table. Drop the pins (horizontally) onto the surface of the
water. Record the number of pins you are able to ﬂoat on the surface.

Number of pins ﬂoated on water:

 

Watch as a student tries to ﬂoat pins in a beaker ﬁlled with alcohol. Record the
number of pins ﬂoated on the surface.

Number of pins ﬂoated on alcohol:

 

2. Did more pins ﬂoat on top of the alcohol or water? Why?:

Pouring Water into a Bucket

Most people have observed the phenomenon of water being poured into a bucket
directly below the source from which the water ﬂows. Watch the demonstration
of the students pouring water from a beaker into a bucket located a few feet to
the Side of the source.

3. Explain why the water does not run all over the ﬂoor.

4. What enables the water to ignore gravity and travel horizontally along the

string?

177

 

Testing Your Understanding:
5. Why does it hurt so much when you perform a perfect belly smacker into a

pool of water?

6. Name a liquid into which you could fall that would cause less pain to your

belly.

7. Why does ice ﬂoat in liquid water?

8. Why are rain drops actually almost perfectly round until they hit something?

9. Which substance would have a higher boiling point, H2O or H2S?. Why?

10. Name at least one substance that would have stronger Hydrogen Bonds than

H20.

178

Appendix I

Various Lab Assessment Activities

Part 10 - Solutions and Solubility Assessment

Teacher notes:
This series of demonstrations and mini-labs requires signiﬁcant
preparation but is very popular with the students.
Student information:
Please follow the directions given for each of the following sections of this lab
assessment. The Ice Cream demonstration will be performed for you by the
teacher, but you will have to perform the rest of the activities yourself. Be sure to

follow the directions carefully and answer the associated questions.

ICE CREAM

Because of the time required, your teacher will make the ice cream for you. You
should listen to his explanation of how the ingredients are combined, periodically
observe the ice cream, and answer the following questions

1. When making ice cream we add salt to crushed ice. Why does the salt melt

the ice?

2. A saltwater solution is called brine. Identify the solute and solvent in brine:

3. What state or phase of matter does the salt in brine demonstrate?

179

 

4. Salt is not normally found in this phase at standard conditions. How would we

normally produce this phase of salt? (without dissolving it)

5. Is dissolution an endothermic or exothermic process?

6. How does the use of salt allow us to produce temperatures below the normal

freezing point of water that are necessary to make ice cream?

SODIUM ACETATE
A. Obtain a test tube of liquid sodium acetate (NaC2H302).
8. Carefully add a single crystal of solid sodium acetate to the solution.
C. Watch and feel the bottom of the test tube and observe the changes

that occur.

7. What evidence did you observe that the sodium acetate (NaC2H302) must

have been a supersaturated solution?

8. What evidence did you observe of a crystal lattice during this demonstration?

9. Is precipitation an endothermic or exothermic change?

10. How is a supersaturated solution prepared?

180

 

 

WAVE BOTTLES:

A. Carefully pour lamp oil or lighter ﬂuid into a clean plastic pop bottle
until it is 1l3 full.

8. Carefully add water to the bottle until it is completely full. If you used
colorless lamp oil or lighter ﬂuid then you can add a few drops of food
coloring at this time to make your wave bottle more attractive.

C. Screw the cap tightly onto the bottle and seal the cap using electrical
tape.

D. Wash the outside of the bottle and check to make sure that it doesn't
leak.

E. Please answer these questions.

11.Why doesn’t the oil and water in the wave bottle mix? (Please use your

chemistry to explain this — don’t tell me “because they're insoluble”)

12. What is the technical term for liquids that are insoluble in each other?

13. Explain why the food coloring will dissolve in the water but not the oil:

14. Identify the solute and solvent in a waterlfood coloring solution:

181

 

ACETONE 8. FOAM CUPS
A. Place a foam cup in a glass dish. (Foam cups are made by bubbling
nitrogen or some other relatively inert gas through liquid plastic as it
cools.)

B. Pour 20mls of acetone (nail polish remover) into the cup and observe

what happens.

15. What happened to the cup?

16. What does a chemist mean when they say that “Like dissolves like"?

17. Since acetone is a non-polar organic substance, what assumptions can you

make about plastic foam cups?

18. What do these same assumptions tell you about water?

19. What are some of the advantages and disadvantages of using the method

you explored in this activity to recycle foam cups?

182

 

Popcorn rocks and crystals

A. Obtain a small sample of Argonite (a.k.a. Popcorn Rock) from the
teacher.

B. Place the sample in a small beaker and cover it just enough vinegar
(4% acetic acid) to submerge the sample.

C. Observe what happens to the sample as it sits in the vinegar.

D. The teacher has prepamd other samples for you over the last few days
so that you can see what will eventually happen to your sample.

20. What happens to the Argonite when it is submerged in the vinegar?

21 . Is this an example of a physical or chemical change?

22.At what point does this change stop? Why?

23. What will happen to the vinegar in this setup over the next few days?

24.What happens to the solute in this setup over the next few days?

25. The ﬁnal product of this investigation is a clump of Argonite crystals that
resemble popcorn. Why are these crystals so different in appearance than the

original Argonite rock?

(Hint - Why are diamonds and coal different if they are both made of carbon?)

183

Appendix I

Various Lab Assessment Activities

Part 11 — Supersaturation Mini-Lab

Teacher notes:

The students really enjoy this hands-on example of supersaturation.

Student lnfonnation:

Wear safety goggles at all times. 00 not touch the sodium acetate solution.

Procedure:

1. Obtain a supersaturated solution of sodium acetate Na2C2H302. This was
prepared by dissolving 4.5 grams of sodium acetate in 2 mls of water, heating
the solution until it dissolved, and than letting it cool. Your solution will
probably be a little warm when you get it (it is more stable and easily moved
this way), so you will have to let it Sit quietly while it cools.

2. When your solution has cooled to room temperature add one small crystal of
sodium acetate to the test tube and record all of your observations (including
how warm the bottom of the test tube feels) in the data table and answer the

analysis questions.

184

Table 13 — Supersaturation Data Table

 

Observations

 

Test tube before adding

crystal of sodium acetate

 

Test tube after adding

crystal of sodium acetate

 

 

 

 

Analysis:

1. What is a supersaturated solution?

2. Why does the test tube change temperature after the crystal is added?

3. Points A, B, and C on the solubility chart on the next page indicate three
different concentrations of sodium acetate in water. Using this chart, describe
the solutions using the terms unsaturated, saturated, and supersaturated. In
the second column please describe how these solutions could be produced,
and in the third column indicate what would happen to the solution if a crystal

of sodium acetate were added to the solution.

185

Table 14 - Supersaturation Description Table

 

 

 

 

 

 

 

 

 

Solution How was the solution What happens to the
Description produced? solution if a crystal of
the solid is added?
S olub111ty Chart
8
i‘
a B
m
S

 

Temperature

Figure 5 — Supersaturation Solubility Chart

186

 

 

Appendix I

Various Lab Assessment Activities

Part 12 - Open-Ended Hydrates Lab

Teacher notes:
This open-ended lab is intended to evaluate the Ieaming that occurred
during a previous lab in which the student experimentally determined the
water of hydration in a compound. Students should be capable of writing
and performing an acceptable procedure. The teacher should decide if the

students will be allowed to refer to their lab notebooks.

Student information:

Part A

Demonstrate you understanding of hydrates by experimentally determining
which of the following are hydrates. (The water of hydration normally indicated in

the chemical formulas of the hydrates has been omitted for obvious reasons.)
CuSO4 M9804 NaCI Na2CO;
Outline the steps you will use to accomplish this in the space provided. You may

use whatever number of steps you wish - but please be complete and remember

that part of your grade will be determined by your procedure write-up.

187

Experimental Procedure: (add steps as necessary)
1.
2.
3.
4.

5.

 

After receiving your teacher’s permission, use the data table to record your

observations and results as you follow your procedure.

 

Table 15 — Hydrates Lab Data Table

 

 

 

 

 

 

Is this compound a
Substance Observations Hydrate? (Yes/No)
CuSO4
M9504
NaCI
Na2003

 

 

 

 

 

188

 

Part B

Experimentally determine the empirical formula of a compound assigned to you
by the teacher. Outline the steps you will use to accomplish this in the space
provided below. You may use whatever number of steps you wish - but please be
complete and remember that part of your grade will be determined by your
procedure write-up. Be sure to design your own data table and include all your
data and show your calculations. Clearly label all data. (Neatness counts!)
Experimental Procedure: (add steps as necessary)

1.

2
3
4.
5

189

 

Teacher notes:

Appendix I

Various Lab Assessment Activities

Part 13 - Water Rockets Investigation

This activity is suitable for evaluating the student’s understanding of

chemical reactions and thermodynamics. It can also be adapted for use in

a Physics class as a demonstration of impulses and the Law of

Conservation of Momentum. The pipet rockets sometimes ﬂy thirty feet!

A launching device will have to be constructed by the teacher prior to this

activity. I have made these launching devices three ways:

1.

Modifying a plaza-electric cigarette lighter - this requires you to
solder some extended leads to the end of the lighter. This type
of launcher is prone to mechanical failure.

Using a Tesla Coil to provide the spark — the pipets are erected
on nails mounted in a wooden launcher and a spark is allowed
to jump from the tesla coil to the electrically grounded nails. This
type of launcher fails if the spark doesn’t jump through the
mixture of gases. When the launcher is suitably engineered it
will allow for mass launches of twenty rockets or more at once!
Using a piezo-electric igniter from a gas grill - this is the easiest,
most sure-ﬁre method of launching the rockets. It requires no
pre-assembly, is easy to manipulate by the students, and isn’t

prone to the electrical shorting common in the other launchers.

190

 

 

Student lnfonnation:

Hydrogen is a clear, colorless gas that is said to be “combustible” - meaning
simply that it can burn quite readily. Oxygen is also a Clear, colorless gas that is
said to “support combustion“ meaning that it must be present for combustible
materials to burn. In this lab, you will be generating, collecting, and reacting
hydrogen and oxygen gas. Hydrochloric acid will be reacted with zinc to generate
the hydrogen. Hydrogen peroxide will be added to manganese metal to generate
the oxygen. (Hydrogen peroxide decomposes by itself to produce water and
oxygen, at a slow, imperceptible rate; the manganese oxide “nlst” which is
coating the manganese metal acts as a catalyst to speed-up this reaction.) You
should ignite different hydrogen/oxygen mixtures to attempt to determine the
most reactive mixture. Both gases are needed for combustion to occur. The trick
is to get the right proportions! In a counter-intuitive manner, water rockets that
contain a small amount of water often ﬂy further! This is an interesting example of

the Law of Conservation of Momentum.

Procedure:

1. Putonyourgoggles.

Cut off a plastic pipet so that it has a neck less than 1 cm long.

Fill the pipet with water.

.599.”

Invert the water-ﬁlled pipet over the oxygen-generating test tube your

teacher has set up. Let the oxygen displace some of the water from the pipet.

191

5. Place your pipet (that is now partially ﬁlled with oxygen) over your teacher’s
hydrogen-generating test tube so that hydrogen displaces some of the
water in the pipet.

6. When you are ready, place your pipet on the ﬁring device at the teacher’s
desk. This device will produce a spark. If you have an explosive mixture in the
pipet - this will launch your pipet towards the target.

7. Answer the following questions.

Please answer the following questions about the Water Rockets
Investigation:
1. What is the balanced chemical equation for the reaction that occurs in the

hydrogen generator?

2. What is the balanced chemical equation for the reaction that occurs in the

oxygen generator? (Keep in mind that the manganese is only a catalyst.)

3. Which will have to be replaced ﬁrst: the zinc in the hydrogen generator or the

manganese in the oxygen generator?

4. What is combustion (burning)?

5. What proportion of hydrogen and oxygen produced the most explosive

mixture?

192

 

10.

Why was this mixture the most explosive?

Write the balanced chemical equation for the reaction of hydrogen with

oxygen:

Why doesn’t the hydrogen and oxygen in the pipet react as soon as they mix?

If a small spark is needed for a small pipet of hydrogen and oxygen, why don’t
you need a proportionally larger spark to ignite an entire room full of hydrogen

and oxygen?

Use the gas laws to explain why the pipets go ﬂying when the mixture within

them is ignited:

193

Appendix I

Various Lab Assessment Activities

Part 14 — Logic Problem

Teacher notes:

This demonstration encourages the students to use careful observations

and logic to identify the solutions in four containers. A guided discussion

about the sample logic problem may help many students with this

deductive process. Prior to the demonstration the teacher should arrange

the following materials on the lab table:

A ﬂask with 150 mls of 1M ammonium hydroxide.

Beaker number one with 25 mls of water and a few drops of
phenolphthalein.

Beaker number two with 25 mls of dilute magnesium chloride.

Beaker number three with 25 mls of dilute copper (ll) sulfate.

To perform the demonstration the teacher simply pours a small amount of

ammonium hydroxide from the ﬂask into each of the three beakers. This

will cause these three relatively colorless solutions to change to red, white,

and blue.

Student information:

Using careful observations, some logic and a few clues, you are to determine the

identity of four solutions based on what colors the solutions displayed as the

teacher performed the demonstration. The solutions used are copper (ll) sulfate,

phenolphthalein, ammonium hydroxide, and magnesium chloride.

194

Procedure:
1. Study the sample logic problem to re-familiarize yourself with deductive logic.
Carefully observe the demonstration.

Indicate what ﬁnal colors you observed in the different pieces of glassware.

9.0)!“

Use the chart to determine what solutions were in each piece of glassware.

Please record the color of the solution that you observed at the end of the
demonstration.
Flask 1" Beaker 2"" Beaker 3" Beaker

Color". Color: Color: Color:

 

Clues:

1. Ammonium hydroxide is a base.

2. When phenolphthalein and a base are mixed they turn a bright red color.

3. Magnesium chloride will form a white suspension when reacted with
ammonium hydroxide.

4. Phenolphthalein was not mixed with copper (ll) sulfate

195

Table 16 - Logic Problem Data

 

Phenolphthalein

copper
sulfate

Ammonium

hydroxide

magnesium

chloride

 

Flask

 

Beaker

#1

 

Beaker

#2

 

Beaker

 

 

 

 

 

 

Your solution:

Identity of the solution in the ﬂaslc
Identity of the solution in beaker 1:
Identity of the solution in beaker 2:
Identity of the solution in beaker 3:

 

 

 

 

196

 

 

\

Logic Sample Problem

This sample problem is designed to familiarize you with the strategy used to
solve logic problems like the one you will be solving in this exercise. These
problems typically ask you to match certain materials with their characteristics by
using clues and a little deductive logic. A simple device used to solve these
problems is a chart that allows you to visualize the comparisons and eliminate

the choices that are inconsistent with the clues.

Sample Problem:

Your teacher has asked you to set up a chemistry lab that used the following four
materials: copper nitrate, calcium carbide, bromine, chlorine

The teacher has decided to test your chemistry skills and logical abilities by
asking you to set up the lab correctly after they leave the room. The teacher said
that even though they had forgotten to label the containers they were sure that
you could ﬁgure out which material was in each container if you just thought it out
carefully. When you went to the lab you found the following:

1. A sealed glass tube of green gas.

2. An open ﬂask with a blue liquid.

.0’

An open beaker with a granular gray solid.

A sealed ﬂask with a red liquid.

.0' :5

A note with the following clues:

197

 

The Clues

1.

2.

You must keep the green gas sealed because of its poisonous fumes.
Chlorine is not a red liquid.

Neither copper nitrate nor calcium carbide must be kept in sealed
containers.

The red liquid is not a compound.

Chlorine and calcium carbide are safe handle only when perfectly dry.

The blue liquid is an aqueous solution.

Table 17 - Sample Logic Problem Data

 

Green Blue Gray Red

gas liquid solid Liquid

 

copper
nitrate

 

calcium

carbide

 

bromine

 

chlorine

 

 

 

 

 

 

 

198

 

The Process:

A.

The ﬁrst step is to carefully read over the clues and place marks in the chart
that represent what you know. X’s are used to indicate impossibilities and O’s
are used to indicate things that can be proven by using the clues.

Clue #1 does not help us at ﬁrst - it may be useful later on.

Clue #2 eliminates the possibility of chlorine being the red liquid so place an X
in the square that is the intersection of chlorine and Red liquid.

Clue #3 in conjunction with clue #1 proves that neither copper nitrate or
calcium carbide can be the green gas so place X’s in the ﬁrst square of the
copper nitrate and the calcium carbide rows.

Clue #4 proves that the red liquid can not be either copper nitrate or calcium
carbide so place X’s in those squares.

Looking at your chart you should now see that there is only one possibility left
for the red liquid. It must be bromine! Place an O in that square.

If bromine is a red liquid than it can not be a green gas, a blue liquid, or a

gray solid. Place X’s in those squares.

. You should now see that there is now only one possibility for the green gas. It

must be chlorine! Place an O in that square.

Since chlorine is a green gas it can not be the blue liquid or the gray solid, so
place X’s in those squares.

This still leaves a few blanks on your chart so you will have to keep reading
the clues to determine which material is copper nitrate and which is calcium

carbide.

199

 

K Clue #5 does not help much by itself, but in conjunctions with clue #6, you
should be able to see that calcium carbide can not be the blue liquid.
Therefore, calcium carbide must be the gray solid!

L. The process of elimination shows that copper nitrate must then be the blue

liquid.

If you have followed the logic carefully, you should now be able to indicate your

solution to the sample problem:

The sealed glass tube of green gas is

 

The open ﬂask with a blue liquid is

 

The open beaker of gray solid is

 

The sealed ﬂask with a red liquid is

 

200

 

Appendix I

Various Lab Assessment Activities

Part 5 - Exploring pH with Indicators Performance Task

Teacher notes:
Before beginning this activity the students should have a beginning
knowledge of how to use indicators.
Student lnfonnation:
You will use a variety of indicators to determine the pH of three solutions. The ﬁst
solution is 0.1 M ammonium hydroxide. The second solution is 0.1 M acetic acid.
The third solution will be an unknown.
Procedure:
1. Place 5 drops of the solution to be tested into a single well in your microplate.
2. Add 1 drop of an indicator to the well and observe what, if any, color change
occurs. Compare this to the table entitled pH Ranges of Common Indicators.
3. Repeat steps 1 & 2 as needed until you have determined the pH of the
solution °

4. Follow these same instructions for all three solutions.

Results:

pH of 0.1 M ammonium hydroxide:

 

pH of 0.1 M acetic acid:

 

pH of an unknown solution

 

201

 

 

Table 18 - pH Ranges of Common Indicators

 

Color Below

Color Above

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indicator Lower pH Indicator Range Higher pH
Methyl violet Yellow 0.0 - 1.6 Blue
Thymol blue Red 1.2 — 2.8 Yellow
Methyl yellow Red 2.9 - 4.0 Yellow
Bromophenol blue Yellow 3.0 - 4.6 Blue
Congo red Blue 3.0 — 5.0 Red
Methyl orange Red 3.2 - 4.4 Yellow
Methyl red Red 4.8 - 6.0 Yellow
Litmus Red 5.5 - 8.0 Blue
Bromothymol blue Yellow 6.0 - 7.6 Blue
Phenol red Yellow 6.6 - 8.0 Red
Phenolpthalein Colorless 8.2 - 10.6 Red
Thymolphthalein Colorless 9.4 - 10.6 Blue
Alizarin yellow Yellow 10.0 - 12.0 Red
Indigo carmine Blue 1 1.4 - 13.0 Yellow

 

 

 

 

202

 

Appendix I

Various Lab Assessment Activities

Part 16 - Neutralization Performance Task
Teacher notes:
In this activity the students will be required to demonstrate their
understanding of acid/base neutralization. They will also be required to
analyze their experimental results against the theoretical yield.
Student lnfonnation:
As you perform this experiment, record your observations and calculations. Be

sure to answer the analysis questions when you are ﬁnished.

Procedure:

1. Determine the combined mass of your evaporating dish and watch glass.
These must both be clean and dry.

2. Add 1 drop of phenolpthalein and 5 mls of 1 M NaOH to the evaporating dish.
Record your observations on the data sheet

3. Stoichiometrically determine how many mls of 0.5 M HCI will be needed to
neutralize the NaOH being sure to show all your calculations on the data
sheet.

4. Calculate the theoretical amount of salt that will be produced by this reaction
— be sure to show all your calculations on the data sheet.

5. Neutralize your NaOH with the amount of HCI that you calculated in step 3.

Record your observations on the data sheet.

203

 

6. Cover the evaporating dish with the watch glass and heat it according to the
teacher’s instructions. Evaporate the solution to dryness. Record your
observations on the data sheet.

7. Determine the actual mass of salt produced.

8. Compare your actual yield with your theoretical yield and determine your
percent error. Show all your calculations. Then dispose of your materials as
instructed.

Observations:

Step 2:
Step 5:
Step 6:
Calculations: (Please clearly label all data.)

Step 3. How many mls of 0.5 M HCL will be needed to neutralize the
NaOH?

Step 4. What is your theoretical yield of salt?

Step 8. What is your percent error?

204

Analysis:
1. How does the product that was prepared in this experiment compare with the

same product as it is produced commercially?

2. Why should you NOT taste the residue from this reaction?

3. How could you determine whether phenolphthalein remains in the residue of

this reaction?

205

Appendix I

Various Lab Assessment Activities

Part 17 — Polymer Tape Lab Assessment

Teacher notes:
The students will be investigating the nature of a common polymer —
plumber’s tape (polytetraﬂuoroethylene). This activity will examine the
student’s ability to apply their understanding of polymers and organic

nomenclature to a real-world application.

Student lnfonnation:

Today you will be looking at the physical properties of plumbers tape. This tape
is wrapped around the ends of threaded pipes. The slippery tape allows the pipes
to slide together tightly and form a water-tight seal without welding. This tape is
not sticky and feels like silk. It must be handled carefully or it will roll up into a

knot!

Directions:

1. Cut a four-inch piece of plumber’s tape using scissors.

2. Carefully lay out the tape on a desk and write a word or two in the center two
inches of the tape. (I ﬁnd the tape is difﬁcult to write on if I drag the pen; it

seems to work better if I just dot the pen across the tape.)

206

 

Analysis:

1

This tape will only stretch in one direction. Try not to stretch the ends,
which will act as handles later on. Which direction does the tape stretch

(sideways or lengthwise)?

This tape is a polymer. How does this explain the incredible stretching

ability of this tape?

What happens to the stretched tape when you pull on the two ends?

Can you pull the tape back into its original shape so that your message is

again legible?

What must be happening to the molecular chains when the tape is being

stretched?

What happens to these chains when the tape shears widthwise?

What is the organic name of the following compound?

F F
\ 1
c=C
1 \

F F

207

10

This compound's common name is a 6-letter acronym made from the

organic name. What is it?

Since this tape is made by polymerizing the compound you named in
question number 7, the correct name for the tape simply has the preﬁx
poly added to the front of the organic name. What is the correct name for

this tape?
Now that you know a little more about this tape's molecular structure and

physical properties, please suggest some reasons why this tape is so

useful in connecting threaded pipes:

208

Bibliography

209

Bibliography

Annenberg/CPS Assessment Workshop. What’s the Point? Assessment in Math
and Science. Providence, RI. Annenberg Institute for School Reform.
1998

Beach, DH. and HM. Stone. Provocative Opinion: “Survival of the High School
Chemistry Lab“. Journal of Chemical Education. 65, 619 (1988).

Beach, DH. and HM. Stone. Provocative Opinion: “Survival of the High School
Chemistry Lab”. Journal of Chemical Education. 65,620 (1988).

Becker, Robert. “Final Analysis — Rethinking an Age-Old Practice”. Journal of
Chemical Education. 72, 816 (1995)

Benchmarks for Science Literacy: Project 2061. New York: Oxford University
Press. 1993. p. 297

Bloom, Benjamin S, Thomas Hastings, and George F. Madaus. Handbook on
Formative and Summative Evaluation of Student Learning. 1971

Busik, Kathy. Clapping Hands. Michigan Assessment Team Assessment
Guidebook, Lansing, MI. Michigan Department of Education. 1995

Carlson, Dale. “Changing the Face of Testing in California”. California
Curriculum News Report. Jan-Feb. 1991. p. 1.

Hart, Diane. Authentic Assessment: A Handbook for Educators. Menlo Park, CA:
Addison-Wesley Publishing Company Inc. 1994, p. vi

Hart, Diane. Authentic Assessment: A Handbook for Educators. Menlo Park, CA:
Addison-Wesley Publishing Company Inc. Menlo Park, CA. 1994, p. 46

Hein, George. Expanding Student Assessment. ed. Vito Perrone. Alexandria,
VA: Association for Supervision and Curriculum Development. 1991. p.
106.

Hein, George. Expanding Student Assessment. ed. \ﬁto Perrone. Alexandria,
VA: Association for Supervision and Curriculum Development. 1991. p.
116.

Hunter, Paul and Sheldon Knoespel. Fire and Ice Demonstrations. Lansing, MI:
Michigan Science Teachers Association Conference. 1994

Institute for Chemical Education. Laboratory Assessment Builds Success.
Berkeley, CA. University of California Press. 1990.

210

Lang, Mozell. “Ways of Getting at Understanding". Michigan Assessment Team
Assessment Guidebook. Lansing, MI: Michigan Department of
Education. 1995

Michigan Assessment Team Assessment Guidebook. Lansing, MI. Michigan
Department of Education. 1995

Michigan Department of Education. Model Instructional Unit. ed. Marty
Couretas. Detroit, MI: Michigan Science Teachers Association
Conference. 1996.

Michigan State Board of Education. Michigan Essential Goals and Objectives for
Science Education. Lansing, MI. 1991 p. 1.

Miller, J.R., M. K Heidemann, and J.M. Parker. New Challenges for Educators
in Science and Mathematics. [Online] Available ww.dsme.msu.edu. April
28, 1998.

Mitchell, Ruth. Testing for Leaming: How New Approaches to Evaluation Can
Improve American Schools. New York: The Free Press. 1992 p. 16.

National Science Education Standards. Washington, DC. National Academy
Press. 1996. p. 20.

Shakhashiri, Bassam Z. Chemical Demonstrations: A Handbook for Teachers of
Chemistry. Madison, WI: University of Wisconsin Press. 1983. p. xiii.

Wagner, Maxine. Chemistry The Study of Matter Laboratory Manual. Needham,
MA' Prentice Hall. 1989

Wiggins, Grant. “A True Test: Toward More Authentic and Equitable
Assessment”. Phi Delta Kappan. May 1989. pp. 703-4.

Wiggins, Grant. “Teaching to the (Authentic) Test“. Educational Leadership, Vol.
46. (April 1989). p.41.

211

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