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This is to certify that the
thesis entitled

THE USE OF FOOD IN CHEMISTRY EXPERIMENTS TO
ENGAGE AND ENRICH THE TEACHING IN THE
CLASSROOM

presented by
Brian Michael Topping

has been accepted towards fulfillment
of the requirements for the

Master of degree in Biological Science-
Science Interdepartmental

 

 

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THE USE OF FOOD IN CHEMISTRY EXPERIMENTS TO ENGAGE AND
ENRICH THE TEACHING IN THE CLASSROOM

BY

Brian Michael Topping

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

Biological Science Interdepartmental

2010

 

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ABSTRACT

THE USE OF FOOD IN CHEMISTRY EXPERIMENTS TO ENGAGE AND
ENRICH THE TEACHING IN THE CLASSROOM

BY
Brian Topping

Students often gain more knowledge out of hands on
work. Labs and demonstrations increase knowledge often
more than the book work and notes because they motivate
interest and provide real world application. In an effort
to incorporate labs into chemistry I have developed a unit
centered on food in order to teach a variety of concepts
and lab techniques to high school students. The study of
food can be a tremendous motivator and help students take
interest and ownership in the learning process. The unit
was evaluated for its effectiveness through the use of a
pre and post-test assessments as well as a post survey of
students’ attitudes towards labs and learning science.
This study showed that students’ overall conceptual
knowledge of the various topics related to food increased
as a result of this unit with evidence provided by the

post-test scores.

 

ACKNOWLEDGEMENTS

I would like to extend my gratitude to the Towsley
Foundation for their financial support during my studies at
MSU as well as Merle Heidemann for her assistance through
this process. I would also like to thank my chemistry
students at Ovid Elsie High School for their hard work and
interest in chemistry. Finally I would like to especially
thank my wife, Katie and son Daniel for their support of

all my endeavors big and small!

iii

 

TABLE OF CONTENTS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

List of Tables vi
List of Figures vii
Introduction
Statement of Problem and Rational ..1
Theoretical Framework .3
School Demographics ..7
Food Chemistry Scientific Background .9
Implementation of Unit “in .16
DATA AND ANALYSIS m- - .25
Conclusion .u .40
Appendices
Appendix A - Consent/Assent Letter and Forms ................... .45
Appendix B — Pre and Post Unit Assessment .......................... .49
Appendix C — Post Unit Survey .51
Appendix D - Activities and Labs
I. Calorimeter Lab .53
II. Ester Lab .56
III. Vitamin C Titration Lab .60
IV. McMush Lab .63
V. Homemade Soda .70
VI. Strawberry DNA Extraction .72
VII. Jell-O Lab - .74
VIII.M&M Chromatography .75
IX. Ice Cream Lab .78

iv

 

Appendix E — Results of Assessments and Surveys

 

I. Students’ Pre and Post Assessment
Scores

II. Students’ Post Unit Survey
Results

 

III. Students’ Pre Test Scores
For Each Question
IV. Students' Post Test Scores
For Each Question ........................

Appendix F — State Standards Addressed

 

Bibliography

.81

.82

.83

84

85

.86

 

LIST OF TABLES

Table 1: Overview of Unit and Activities .19

Table 2: Selected Student Profiles .33

vi

 

 

LIST OF FIGURES

Figure 1: Pre and Post Assessment Question Comparison m..26
Figure 2: Selected Students’ Pre and Post Assessment ............ .34
Figure 3: Post Unit Survey Results Questions 1—15 ..................... .37

vii

 

INTRODUCTION
Statement of Problem and Rationale

When I set out to obtain my Masters of Science degree,
I was teaching at a small district in southwest Michigan.
I was teaching Biology, Chemistry, and Environmental
Sciences, the bulk of which was Biology. I began my
studies in the effort to obtain my masters in the
Biological Sciences, which also was my undergraduate major.
I then obtained a job at Ovid-Elsie Area Schools teaching
only chemistry. As I continued through the program, I
wanted to make the topic I choose for my Masters research
apply to both Biology and Chemistry. This led to many
ideas. I ultimately choose Food Chemistry as my focus
because of its multidisciplinary nature.

As I designed the unit, it was my expectation that if
I could engage students through hands—on applications as
well as things that interested them, then the learning
process would be enhanced. I designed a unit that included
nine laboratory exercises that I expected would help
accomplish this goal. Some of these labs were to establish
what organic molecules are and the energy in food
molecules. Others were to identify these molecules as
students learned lab techniques. Many of the labs included

1

notes and lecture to attempt to accommodate different
learning styles. The unit focused around hydrocarbons,
titrations to estimate ascorbic acid content, using
indicators to identify food molecules, functions of
enzymes, energy in foods, DNA extraction, products of
biological processes, and chromatography of food dyes. My
hypothesis was that by taking concepts that I had
previously taught and adapting them to include food as a
theme student achievement on the concepts of heat transfer,
hydrocarbons, titrations, indicators, chromatography,
enzymatic functions, and freezing point depression would

dramatically increase.

 

THEORETICAL FRAMEWORK

Chemistry is the study of matter and the changes it
undergoes. All too often when students begin my
Introduction to Chemistry classes they have this idea that
“I’ll never need to know this stuff!” However, if
presented properly they quickly see that many of the
concepts are a part of so much of our everyday life. “The
aim of science education is to help students develop an
understanding of the natural world: what it contains, how
it works, and how we can explain and predict its behaviour”
(Psillos and Niedderer, 2002). Often times, due to time
constraints in the classroom, we limit the hands on aspect
of what we teach in order to “cover” material and not
follow through on mastery of the concepts with all
students. We acquire durable knowledge through the
interaction of two factors (1) our ability to process and
store information, and (2) the number and frequency of our
academically oriented experiences (Marzano, 2003).
However, “What seems to be critical is not sheer amount of
experience but rather what one had been able to learn from
and do with the experience” (Sternberg, 1985). Based on
these ideas I felt that if I could find something that
would interest students, such as the chemistry of food, the

3

learning process of chemistry for the student would be
facilitated. McManus, Dunn, and Denig (2003) found that
biology students who learned using hands—on manipulative
activities had higher science achievement and science
attitude scores than students who learned using traditional
lecture, reading, and discussion activities. This is
certainly applicable to chemistry students. The also
require topics that are linked to something from everyday
life, and an increased number of experiences with the
topic. Whenever a teacher decides to incorporate a large
number of labs in a class, it is inevitable that results
will vary wildly due to a variety of student errors such as
poor procedures or accurate measurements. However, an
interesting set of studies has shown that simply added
student effort and interest will enhance achievement
(Marzano, Pickering, and Pollock 2004).

Why food chemistry? Chemistry is the study of
composition, structure, and properties of materials and the
changes that they undergo. I chose to title this unit Food
Chemistry to my students because “We also believe there is
a link between the title and the expectation of the science
experience to be fun for the participants” (Skluzacek
2010). According to Richard Owusu-Apenten (2005), by

4

inserting the word “food” before “materials” leads to a
reasonable definition for food chemistry.

Teachers are often confused about their role in
instruction when students are engaged in hands—on-activity.
Many teachers are concerned about an adjustment they may
have to make in their teaching style to facilitate a hands-
on program as well as how students will react to increased
responsibility and freedom. An activity—oriented
classroom, in which hands-on materials are made available
to students, is often a very new experience for the teacher
as well as for his students (Shymansky and Penick 1981).
Before I did my research on this unit, I wanted to do a set
of labs that caught the attention of students in my
introductory level chemistry class. I tried to focus on
four arguments related to labs and active learning as I
completed this work (Bentley and Watts 1989). They are:

1. Passive learning is the staple diet for many

learners in numerous classrooms.

2. Passive learning may suit some learners some of the

time, but it is ineffective for many learners much of

the time.

3. Active learning means involving learners fully in

their own learning, moving some of the responsibility

5

for learning to the learner.

4. Encouraging active learning involves using

different approaches to teaching.
Passive learning is characteristic of traditional lecture
based teaching. This includes practice problems or book
questions. Active learning sometimes called inquiry
learning, engages the students and requires them to take
part in the learning process through lab activities and
student driven studies. In one of our units we were
discussing freezing point depression, a concept in its
simplest form is probably very easily grasped by many
students through lecture. I wanted to involve active
hands-on learning, so we set out to make homemade ice cream
to demonstrate this concept. I had never had my students
so interested in a topic and their test results showed a
good grasp of the material. In my biology class I had the
students set up and conduct their own experiment to
demonstrate the importance of variables and controls
involving vegetables in the greenhouse. Again, their
interest and involvement was noticeably higher. This
activity showed me the benefit of motivation and engagement
through inquiry learning. As I did more research on this
topic, I came across some literature involving food in the

6

 

classroom. Students certainly develop a more personal
connection to chemistry. Taking familiar substances such as
lasagna and discussing its chemical profile of fats,
carbohydrates, and proteins and then tasting it enables the
student to interact with

complex concepts and build their own concepts (Sterling and
Davison, 1997).

Greater emphasis should be placed on learning the
skills of investigation and inquiry in the study of
science, with the laboratory and experimentation playing an
important, but not exclusive, role (Fraser and Walberg
1995). While the food chemistry unit I set up may not be
entirely student driven, I saw the motivation of food
coupled with labs to involve active learning. This led me
to increasingly try to incorporate the interests of my
teenage students trying more hands-on activities as well as
the incorporation of their interests. Through previous
class work, I knew that when this thesis came about I had a

good platform to use.

 

SCHOOL DEMOGRAPHICS

Ovid-Elsie Area Schools is a district that is about 25
miles northeast of Lansing, Michigan. It is about 10 miles
east of St. Johns off US 127. It is an agriculturally
based community that embodies the idea of hard work. The
median income for a family is around $41,000 (IES 2010).
97% of the community has at least a high school diploma,
however for many, this is their highest level of education,
partly due to the high number of family farms in the area.
Only about 10% of the population has a bachelors degree or
higher. I did my study at the High School which houses
about 600 students from grades 9—12. This number has been
fairly consistent for many years. We are on a 3 by 5
trimester schedule. Students have 3 trimesters of 5
classes. Each class is 72 minutes in length with makes
doing labs very convenient. It is a primarily Caucasian
student population (95%).

I choose to target a group of upper level chemistry
students for this study in a class called Chemistry B.
This class is taught in one trimester. All students are
required to take a trimester course called Introduction to
Chemistry which is taught at the lou‘grade level with
mostly concepts with little math and basic lab procedures.

8

 

Many of these students often go on to a trimester class
called Chemistry A which covers some of the introductory
concepts in more depth and higher rigor. About a third of
the students from Chemistry A will go on to take Chemistry
B. This course is an extension of Chemistry A continuing
to cover mostly new topics and a few others with more depth
and mathematical involvement. The majority of students
taking this class are llu‘graders with a few upper level
lOU‘graders. Again, Introduction to Chemistry is a course
in which material is first introduced without mathematical
calculations, strictly concept driven. Chemistry A and B
have a large amount of new material with some of the
concepts of Introduction to Chemistry revisited involving

more mathematical work.

 

FOOD CHEMISTRY SCIENTIFIC BACKGROUND

Students participating in this food chemistry unit
were presented with lecture notes prior to doing the actual
unit. After that, laboratory experiences were used to
strengthen the different chemistry concepts they were
learning about.

One concept commonly taught in high school chemistry
is heat transfer. Heat transfer is the measure of heat
passed from one substance to another since the conservation
of energy law states that energy can not be lost. To teach
these concepts students must understand the basic heat
transfer equation.

Q=M*Cp*AT
Where Q is representing heat lost or gained, M represents
the mass of a substance, and AT represents the change in
temperature. This leads to the Q = Q equation in which the
heat from one substance is absorbed by another. A common
way to show this principle is using what is called a bomb
calorimeter. This is a device that will transfer the heat
released by a substance to water. By measuring the change
in Q of the water we will know the Q lost by the substance.
In a high school setting often times we need to make a
rough calorimeter to show this concept by placing a beaker

10

 

 

or other container above the substance releasing the heat.
By placing a known amount of water remembering that 1 m1 =
1 gram and measuring the initial temperature and the final
temperature after the reaction you can find the heat
released. Some heat is lost to the surrounding air but it
is still a very effective way to show the principle of heat
transfer and provides good practice using the heat transfer
equation and can compare relative heat/energy released.
Another concept discussed in my unit, as well as in
most chemistry classes, is the basic structure of
hydrocarbons. A hydrocarbon is a carbon compound, often in
a chain, with bonded hydrogen atoms. As nomenclature is
taught we often start with simple alkanes, alkenes, and
alkynes. Functional groups are then introduced such as a
hydroxyl group (-OH) replacing a hydrogen, ketones (=0)
replacing hydrogens, and carboxylic acids (COOH). Other
organic functional groups can be formed by combining
different hydrocarbons. This then can lead to the
formation of esters. Esters can be classified as aromatic
hydrocarbons. They emit a strong odor, some pleasant
others not. An ester is created by combining an alcohol
with an organic acid. This process essentially links the
alcohol to the organic acid via the oxygen in the alcohol.

11

This can be a very difficult concept for students to grasp
and understand. Often times they can grasp the functional
group involved but have trouble drawing its structure.
Titrations are another concept taught in most high
school chemistry classes. It is often introduced when
learning about acid-base chemistry. However, the use of
titrations can be expanded to include food composition as
well. Lugol’s solution will turn purple/black when it
reacts with starch. When Lugol’s and ascorbic acid
(vitamin C) are combined in solution, a chemical reaction
takes place. In this chemical reaction, the ascorbic acid
molecule loses electrons, which are transferred to the
iodine (Lugol's) molecule. This type of reaction is known
as an oxidation/reduction reaction. The ascorbic acid is
oxidized to dehydroascorbic acid, and the iodine is reduced
to iodide ions. By measuring the amount of iodine needed
to a known amount of vitamin C we can see just how much
iodine is needed to react with the vitamin C. We know when
this amount is reached because the brown color of the
iodine will not disappear due to reduction. We can then
titrate our iodine with an unknown strength solution of
vitamin C to determine its concentration by adding some
starch to the vitamin C solution. The starch will cause

12

the titration to turn black when the vitamin C has been
completely oxidized.

An easy way to test for the presence of a particular
substance is to use an indicator. The way these indicators
show the presence of the substance can sometimes be very
complex, especially for high school students. There is
value, however, in knowing what they can be used to test.
For example, Lugol’s iodine will indicate the presence of
starch by turning blackish purple. Benedict’s solution
will indicate the presence of simple sugars by turning
reddish orange after heating. Bradford’s solution can
indicate the presence of proteins by changing from a
reddish color to blue. Indophenol can indicate the
presence of vitamin C (ascorbic acid) by changing from a
blue to clear. Silver Nitrate is a good indicator for
sodium chloride (table salt) by changing from a cloudy
clear solution to milky white because of the replacement
reaction producing an insoluble precipitate silver
chloride. Sudan III is a red indicator that binds to
lipids and fats. The color doesn't change but makes the.
lipids stand out.

Fermentation is a concept discussed in biology. It
also has chemistry aspects as well. When yeast is added to

13

sugar water in a closed container the yeast can metabolize
the sugar producing carbon dioxide and alcohol.

C5H1205 -) C02 + C2H50H
This is the basic principle behind the brewing of beer and
how homemade soda such as root beer is produced by using
the naturally produced C02 to carbonate the drink.

DNA is a component of all cells on earth that serves
as an information molecule. You can break open the cells
with detergent by destroying the fatty membranes that
enclose them as well as the nuclear membrane within the
cell. The DNA is then released into the solution, but is
still soluble in water. Detergent and salt also strip away
proteins that are associated with the DNA molecules. DNA
is not soluble in alcohol, but much of the rest of the
cellular molecules are. By adding cold alcohol, DNA
precipitates out of the solution.

Another concept discussed in this unit is the function
of enzymes, biological catalysts. They can have many
different functions, one of which is the disassembly of
proteins. Collagen or gelatin is a very easy protein to
obtain via Jell-O. When it is dissolved in water it
strings together like a matrix of spaghetti noodles to trap
the water. Some enzymes can be isolated from fresh fruit,

14

such as bromelain from fresh pineapple. To show how the

enzymes break down the gelatin you can place fresh

pineapple in gelatin and watch as the

gelatin begins to

liquefy. This can also be used to discuss the effects of

pH and temperature on enzymes as canned pineapple will not

affect the gelatin because the enzyme

is inactivated.

Chromatography is a very simple lab procedure used in

chemistry classes. There are many forms of chromatography

but one of the simplest is chromatographic separation by

particle size. This process works well with ink, as it

contains many different dyes which can be separated using

some filter paper and a salt water alcohol solution. This

solution will travel up the filter paper and dissolve the

ink causing it to travel as well. The process of

chromatography can also be applied to
foods. Dissolved dyes from M & M can
paper and chromatographed in the same

colors work the best for illustrating

they are made up of more than one dye.

separation is a piece of filter paper
and yellow bands.

The making of ice cream is based

different dyes in

be applied to filter

way. Brown and green

separation because
The result of this

containing blue, red,

on a common chemistry

concept known as freezing point depression, a property of

15

solutions that causes the normal freezing point to be
lowered. By adding salt to ice you prevent the water
molecules from crystallizing allowing the temperature to
decrease significantly below its normal freezing point.
This process can be illustrated by making homemade ice-

cream.

16

IMPLEMENTATION OF THE UNIT

This food chemistry unit was implemented in two
sections of my Chemistry B class in the 2009-2010 school
year. It is a trimester course made up of 72 minutes per
day for 12 weeks. I chose to teach this unit at the end of
the trimester before final exams and after discussing many
of these principles prior to teaching the unit. The intent
of this unit was to provide the students with a hands-on
learning experiences relating to the concepts of heat
transfer, hydrocarbons and esters, use of indicators,
enzyme function, anaerobic respiration, chromatography, and
freezing point depression. A total of 32 students give
consent and assent to the study.

This unit was previously taught without data
collection in 2007-2008 and 2008—2009 for a variety of
reasons. In the first year, 2008, I only had one Chemistry
B class and of the 20 or so students only 10 gave consent
for using their data. In the second year, 2009, I again
only had one chemistry B class, and it was made up of
largely sophomores and foreign exchange students. I chose
not to include these students’ data because of the atypical
nature of this class. In this school year, 2010, I had two
classes that participated, which were fairly typical.

17

This year’s 2009-2010 unit was conducted during the spring
trimester from late April to early May. This also
presented some problems because of the large number of
school-based activities requiring students to be out of
school and missed labs. I have chosen to include all 32
students who provided assent and consent even if they
missed a day or two. Many of the students missing class
completed the material on their own time. If they were
excessively missing they were excluded from the study.
Students took a pre and post-test (Appendix C),
consisting of 14 open ended questions, so the student can
write as much information as they can. Students also took
a post unit survey (Appendix B) consisting of 15 questions
ranking what they enjoy and don’t enjoy about the
laboratory setting. The sequence of events for this unit
is summarized in Table I. The unit was designed to require
about two weeks to complete all activities and was based
primarily on concepts that had already been discussed. For
many of the labs, students had participated in discussions
before doing the lab as well as during lab activities, such
as chromatography lab, when students were waiting for
results. The notes and discussions were presented through
PowerPoint® notes, as well as through the pre lab write-up

18

given the day before the lab. The concepts of heat
transfer, chromatography, hydrocarbons, and enzymes had
already been taught to them in the Introduction to
Chemistry and Chemistry A course.

Table 1: Overview of Unit and.Activities (State Standards

expanded in Appendix F)

 

 

 

Day Topics and Lab Activities State Standards
Covered Covered

Day 1 Introduced Food Chemistry C1.1C
Unit, labs, and expectations

Day 2 Reviewed heat transfer and C3.1X

how to make calculations
using Q=M*Cp*AT

 

Day 3 * Nut Lab (Set up basic C3.1C
calorimeter and calculate
calories in nuts and other

 

 

 

 

 

 

foods) .
Day 4 Refreshed knowledge on C4.2E, C5.8A,
Hydrocarbons and functional C5.8B
Groups
Day 5 * Ester Lab C5.8
Day 6 * Vitamin C Titration Lab C5.7A
Day 7 * Use of Indicators McMush C5.8C
Lab
Day 8 * McMush Lab Continued C5.8C
Day 9 * Homemade Soda Lab C4.5A, C5.2A

(anaerobic respiration)

 

Day 10 * Strawberry DNA Extraction C5.8C

 

 

 

 

 

 

Day 11 * Jell-O Lab (enzyme C5.8C
function)

Day 12 * M & M chromatography lab C1.1C

Day 13 * Ice Cream Lab (Freezing Pt C4.7A
Depression)

 

 

Activities with an * were developed for this unit.

19

Description of Activities

Nut Lab (Heat Transfer) Appendix DI: This activity took
two days. Calorimeters were explained by using heat
transfer equations and working through practice problems.
Students had worked with examples of heat transfer
equations before this Food Chemistry unit. A variety of
different nuts were used to determine caloric content.
Most nuts worked well because of the high amount of oils in
them, allowing them to burn easily. Some of the best nuts
were peanuts, cashews, walnuts, Brazilian nuts, and
almonds. Once students have determined the initial water
temperature, they set the nut on fire using a lighter. We
talked about a slight error due to the lighter and that it
can be offset due to the large amount of energy we are
losing to the open air around it. The set up is a paper
clip stuck into a Styrofoam cup with a nut balanced on it.
Over the nut is a beaker of water with 100 ml in it.
Students are often confused by the large calorie numbers
obtained. They investigate why they are so large, helping
to illustrate the difference between scientific calories
and food calories (kilo calories). Students wrote a lab
summary on this activity including purpose, hypothesis,
materials and methods, data, and conclusion.

20

Ester Lab (Hydrocarbons) Appendix DII: This activity was
undertaken after a refresher on hydrocarbons and functional
groups. I used it to make the concept more interesting and
hands—on. Students were asked to make and identify a
variety of esters using organic acids and alcohols. This
isn’t really a food lab, but it produces odors of many
foods familiar to students. Students were asked to explain
the difference between the original alcohol and acid
functional groups and how they change when the ester is
formed. Drawing out and manipulating the new ester
formation was very challenging for them.

Vitamin C Titration (Titrations) Appendix DIII: Students
reviewed their knowledge of titrations from acid base
chemistry and performed them using a variety of fruit
juices. It was difficult to find juices with varying
vitamin C contents due to the fact that many juices are
fortified with ascorbic acid. It may be beneficial to make
your own juices from fresh fruits to get realistic
readings. The titration was done using Lugol’s solution as
a reagent and indicator. Students won’t notice a color
change with the excess starch added until the acid was
converted to ascorbate.

MbMush Lab (Indicators) Appendix DIV: This easily was the

21

 

favorite lab of the students. McDonald’s® happy meals were
blended and tested for the presence of different food
molecules such as proteins, fats, starch, sugar, vitamins,
and minerals. These molecules were not discussed much
prior to this lab. It was a difficult lab to see
colorimetric results on some tests using the indicators
because of the dark color of the mush, but it was possible.
Students enjoyed it, however, because they liked the idea
of blending McDonald’s® foods together and determining just
how much fats there was in it.

Homemade Soda (Anaerobic Respiration) Appendix DV: We
discussed the yeast as a living creature that must
metabolize sugar to survive, and in the process, give off
carbon dioxide and alcohol. Students were presented with
information about respiration and fermentation. Students
in groups of 2 or 3 made different flavors of soda. They
were surprised by the high amount of sugar needed and the
yeasty taste of the product. The finished product must be
left in the fridge for at least 2 weeks or the flavors are
very strong and yeasty.

Strawberry DNA Extraction (Solubility) Appendix DVI: We
discussed the lipid bilayer around a cell as well as how
DNA is a hydrocarbon with nitrogen bases. We crushed the

22

cell walls and used detergent to break the cell and nuclear
membranes. Then we precipitated with alcohol to bring the
DNA out of solution. It produced a jelly like string in
the solution which was the DNA.

Jell-O Lab (Enzyme Function) Appendix DVII: Students
learned about the basics of enzyme function and used this
lab to visualize enzymatic breakdown. Jell-O is made up of
collagen, a connective protein. I explained that collagen
gets dissolved and traps the water molecules as it sets.

We crushed up fresh pineapple to get the bromelain enzyme
and added it to our Jell-O molds. Students found the molds
without pineapple set up and those with don’t. We
discussed specificity of enzymes and other examples, such
as amylase.

MEM Chromatography (Chromatography) Appendix DVIII: In
this activity we used chromatography to separate substances
dissolved in a solution by size. The primary function of
this lab was to show the lab technique of chromatography
using something other then ink pens that would interest
them. The bands that were present after running the dyes
on the filter paper were not easy to see. If you looked
closely reds, blues and yellows were observed.

Ice Cream.Lab (Freezing Point Depression) Appendix DIX:

23

This activity was used to teach freezing point depression.
It was a good lab to end the food chemistry unit because it
is not a difficult lab to set up and required the students
to bring in a lot of their own materials. If timed
correctly, students can make floats from their homemade pop
and ice cream. Students made their own ice cream solution
of sugar, milk and vanilla from the directions given to
them. Students then took the temperature of just the ice
before adding salt as well as after they noticed the ice
cream solidifying. It can be a messy lab and could be
altered into a whole class activity using an ice cream
maker to limit the mess, but that would not be as much fun

or hands—on.

24

DATA.AND ANALYSIS

After reviewing assessments used for data collection
in 32 consenting and assenting students, I graded their pre
and post-tests (Appendix B) on a 3 point scale per
question. If the student touched on an idea but didn’t
elaborate or explain, they receive a 1. If the student
introduced an idea and had some explanation but could have
given more information, they received a 2. If the student
gave a complete answer with good explanations, they
received a 3. The total number of possible points for the
pre and post-test was 42. The results for each question are

shown in Figure 1.

25

FIGURE 1: Pre and Post Assessment Question Comparison

 

Student Average Pre vs Post Assessment Percent

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   

 

 

          

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Scores (F32) l Pre Assessment
90 - Percent
80 i .1 El Post Assessment
70.; 1 pi? Percent
604—: H ‘ I“
5014—3 — — r: . “I
Percent 40*? I 'I L _ _l_3_F_ 43.3.1
30. “ ‘ T ”LI“
2r;:;§ .zzfi--*45
10.; ’ i; :3 S I' -~§ -I-
of 'Ii IMV

 

 

12 3 4 5 6 7 8 91011121314
Question Number

 

 

 

26

Item.Ana1ysis

Question 1: What is a hydrocarbon? For a student to get
full credit they needed to say that it was a molecule made
up primarily of hydrogen and carbon, was organic, and the
carbons formed chains. The average increase from the pre-
test to the post test was 62%.

Question 2: How do we name hydrocarbons? Full credit I
explanations mentioned the number of carbons in the longest
chain, types of bonds between the carbons, and if they
presented functional groups. Average increase from pre
test to post test was 46%.

Question 3: Explain what a functional group is and give a
couple examples. Students were to show evidence they
understood that functional groups are groups of elements
that bond to the hydrocarbon, changing its behavior or
chemical properties. Some examples we covered in this unit
were organic acids containing a double bonded O and an 0H
as well as alcohols containing an 0H. Increase on this
question from pre test to post test was 34%. It was low
compared to other questions because students did not
explain what they are and simply gave examples.

Question 4: What is a calorimeter? Students were to
explain that it is a device used to measure heat released

27

from a substance when that heat is transferred to water.
Increase on this question from pre test to post test was
34%.

Question 5: How does a calorimeter work? Full credit
explanations included that the substance producing the heat
is below the water, and that as heat is released the water
above it absorbs it. The temperature increases and using
the heat transfer equation the heat released from the
substance can be determined. Average increase for this
question was only 17%. Generally, students’ explanations
lacked sufficient detail.

Question 6: Name the major molecules of food and the tests
we can use to test for them. Complete responses included:
carbohydrates (Iodine or Lugol’s), sugar (Benedicts),
proteins (Bradford’s), vitamins and minerals (variable
tests), and lipids (Sudan III). Increase from pre test to
post test on this question was 70%. This is a large jump
because it is a topic that they had never been introduced
to prior to this food chemistry unit.

Question 7: What is an ester? Students were to explain
that it is an aromatic hydrocarbon made from an organic
acid and an alcohol. I originally expected them to know
how to name them but it was too difficult for them to grasp

28

for the time I had for instruction. Increase on this
question was 69%.

Question 8: Do you think a McDonald’s® meal is a balanced
source of nutrients? This question was open to
interpretation as long as they explained their reasoning
using the science of food molecules. Most said “no” due to
the high lipid and salt levels. Increase was 56% on this
question.

Question 9: What is an enzyme? Students should know that
it is a large protein molecule that acts as a biological
catalyst. Improvement for this question was 41%. Many
students didn’t mention that enzymes are_proteins.

Question 10: Describe how an enzyme works/functions and
give and example. A full credit explanation included that
enzymes are specific to certain substances and that they
break substances down into smaller parts. The two examples
we discussed in class and labs were amylase breaking down
starches and bromelain in pineapple breaking down collagen.
The increase on this question was 44%.

Question 11: When making homemade ice cream you add salt
to ice. What conditions does this create and why? I
wanted students to explain the process of freezing point
depression. They needed to mention that it causes the

29

 

temperature to go below zero because the salt interferes
with the crystallization of the water. Increase was 40%.
Question 12: When we make homemade pop you need to add
yeast to the mixture. What function does the yeast serve
and why do we need to stop the reaction after only a few
days? I wanted the students to understand that the yeast
is a living creature, feeding on the sugar and producing
carbon dioxide and if it’s anaerobic, alcohol (Lee, 1983).
That’s why we need to stop it after a couple days.
Increase on this question was 46%.

Question 13: Some drinks have more vitamin C than others.
How could the amount of Vitamin C be determined in each
drink? How much should we have each day? The students
should explain the titration process using iodine and
starch as titrant and indicator respectively. The ascorbic
acid (vitamin C) will react with the iodine. Once the
vitamin C is converted to ascorbate then the iodine will
react with the starch showing a blue color. They should
have indicated 60 mg per day as a vitamin C requirement as
discussed within the lab. Increase was 61%.

Question 14: Define and explain the process of
chromatography. The students should indicate that it was
the separation of particles in solution by size (in this

30

particular example). It could be a variety of other
processes such as polarity, depending on what you are
trying to separate. Many of the students didn’t explain
the process. Increase on this question was 39%.

Overall the class average increased from a 3.7/42 average

to a 23.8/42 average.

31

Analysis of Individual Students

I also choose to select six students, three male and
three female, with varying skill sets to follow through
this study. These are 2 each of high, middle, and low
performing students based on previous performance on other
class work in Chemistry B. I decided to do this because I
felt that with these students the reader would get a good
idea of how the whole class did regardless of typical
achievement level. In Table 2 the students are listed with
alias names to protect their identity. Figure 2 shows the

pre and post test results for each student.

32

Table 2: Selected Student Profiles

 

Name (Grade)

Student Description (Strengths and
Weaknesses)

 

Alicia (Junior)

This student is a high achiever.
Very punctual and gets assignments
done as soon as possible.

Involved in many extracurricular
activities but not sports.

 

Brad (Sophomore)

This student is much like Alicia.

 

Connie (Sophomore)

This student is a typical middle
performing student. She is not
afraid to ask for help. Involved
in a lot of athletics. Sometimes
gets off task due to socializing.

 

Dan(Sophomore)

This student is very involved in
Future Farmers of America. Is
quiet and on task and willing to
ask for help but can struggle with
tests.

 

Elaine (Sophomore)

This is a student that really has
a difficult time focusing in
class. Isn’t involved in any
extracurricular activities. Very
shy and doesn’t ask for help.

 

 

Frank (Junior)

 

This student enjoys hands on
activities but really struggles
with notes and written work. Not
involved in many extracurricular
activities.

 

33

 

FIGURE 2: Selected Students’ Pre and Post-Assessment Scores

Selected Students Pre vs Post Assessment Scores

H=H' h Achleving
M= onhievlng
L=Log thisvi

 

 

 

 

 

 

 

 

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:323: _ ,- .35; (A .. 73;3;3 II;I;I ;;Z;Z _ V :35 __ new-1mm

 

 

 

Score out of 42

 

15/ .;.;. :-:- :-:-: I

—.—.—-.— —_.—4- e e —-——4. n e n a ..J. c e _4

 

 

10 —/

 

 

 

 

 

 

 

 

 

 

 

Alicia Brad Connie Dan Elaine Frank
Student Alla

34

 

Alicia got a 7/42 on her pretest. She was able to get a
few points on definition type questions, such as what is a
calorimeter or name the major food molecules, but could not
explain how to test for them or expand on how they are
used. After the unit Alicia got a 38/42 on her post test.
She received all 2’s and 3’s on the questions. This result
does not surprise me. She took notes throughout the labs
and wrote with a lot more detail on the topics.

Brad received a 12/42 on the pretest. This is probably due
to having had the some exposure to the material this year
in Chemistry A. He did well on explaining what things
were, but not on how to use or identify them. He did best
on the hydrocarbon questions because it was a unit
discussed last trimester in Chemistry A. On his post test
he received a 38/42. He also didn’t get any 1’s on the
post test and did a good job of elaborating on the chemical
procedures we used for the unit.

Connie only received a 2/42 on the pretest. She knew that
esters had odors and that McDonald’s hamburgers were high
in fats. She didn’t elaborate on any concepts and didn’t
know any of the lab techniques, but she did attempt to
answer every question. On her post test she received a
25/42. She was able to get at least 1 point on every

35

 

question and did a good job on the questions that involved
pre lab notes.

Dan also scored 2/42 points on the pre test. He did
attempt to answer every question but was mostly guessing.
On his post test he got a 26/42. He showed a lot of
improvement on the questions regarding lab technique but
could have explained the procedures better.

Elaine received a 2/42 on the pre test. She didn’t attempt
every question even though she was asked to. On her post
test she got a 20/42. She attempted every question and
missed receiving any points on only two of them. Her
detail was lacking but she did mention some aspects of most
of the concepts.

Frank did not get any points on the pre test. He didn’t
attempt many of the questions and was way off on those he
did. This fits his typical learning on other concepts he
has trouble grasping. He can quickly give up. On the post
test, however, he scored a 21/42. He earned full credit on
a few questions. For most questions he was able to recall
the concept and give some explanation but lacked sufficient

detail and accuracy for full credit.

36

 

Analysis of Post Unit Survey

At the conclusion of the unit the students took a 20
question survey (Appendix B) where they ranked the things
that they enjoy and don’t enjoy about a lab based unit.
Fifteen of the questions were to be ranked from 1 to 5 with
5 representing that they strongly agree with the statement
and 1 representing that they strongly disagree.
Information from the survey will be used to help guide
development of other lab based units. I also included each
of the labs we did to determine if they remembered the
basic principles addressed in each and if they liked a
particular lab or not.

Figure 3 shows the results of the first 15 questions
of the survey. Complete results are found in Appendix EII.

Figure 3 Post Unit Survey Results for Questions 1-15

 

Post Unit Survey Rankings (Q's 1-15) ("'32)

Ihnnmeflutté

 

12 345 6 7 8 9101112131415
(LnflthuMMr

 

 

 

37

 

The highlights of the survey results show that after
this unit, students identify chemistry as an aspect of
everyday life, and that chemistry labs are helpful in their
learning. Students also indicated that they learned a
lot of material through the lecture portion of the class
and that the labs were a good reinforcement strategy. They
also enjoyed the group learning aspect that labs present.
Questions five, twelve, and fifteen had lower scores than
the other questions. Question five asked if lectures and
labs are connected. Student responses stated that they
were neutral. This may have been because these labs were
based on concepts from previous course work and there was a
time gap from the lecture portion. Question twelve asked
if they would prefer individual lab work. As discussed
earlier they enjoyed the group work aspect and didn’t want
to work individually. Question fifteen asked if labs
presented more work for the student. They indicated that
they disagreed. Questions 16-20 were open ended questions
addressing the major principles of each lab in this unit as
well as what labs they enjoyed most and least. Responses
to these questions varied among the students. For question
17, asking what lab helped you learn the concept the most,
the majority of the students answered the.MCMUsh lab and

38

the Ice Cream lab. Nearly all students said that these
labs helped them learn a particular aspect of chemistry.
Some students said that the least helpful lab was the
strawberry lab, without explanation, but most didn’t give

any explanation.

39

 

CONCLUSION

My objective was to develop a unit revolving around
food to improve student comprehension of different chemical
concepts and laboratory techniques. Overall, this unit was
successful in increasing student knowledge on topics that
typically students in my class had struggled with. Those
topics were heat transfer and caloric energy, enzyme
function, hydrocarbons and functional groups, and freezing
point depression. Evidence of this growth can be found by
looking at student pre and post test results (Figure 1)
which showed growth in knowledge of the different concepts
addressed. Also, by looking at the post unit survey
(Figure 3) students generally enjoyed the lab—based unit as
well as the group work that it entailed, despite the fact
that they said it created more work for them compared to a
traditional lecture based unit. This unit provided a
hands—on approach and interested them by making it
meaningful through the food aspect. Growth in knowledge
was dramatic and every student’s scores went up, some less
than I expected and others more.

Some of the literature I found when researching this
unit said that increasing the frequency of academic
experiences would show growth in student achievement. I

40

attribute some of this growth and retention to this
increased number of times the topic is covered. This unit
also fostered other questions that interested the students
regarding food. Questions such as what is the content of
other vitamins and minerals in different foods that were
not discussed. These questions provide teaching moments
that are student driven and relate to inquiry teaching.
One of which was students wanted to investigate other
nutritional substances such as potassium in bananas. The
four arguments I focused on by (Bentley and Watts 1989),
for the development of this unit, I believe hold true. By
undertaking this unit I had to change the way I taught
these topics from previous years. It involved more active
learning and students learned throughout the course of the
unit.

In prior years of teaching, I noticed that students
are more invested in the learning when it involves
something of interest to them. The literature by
(Sterling) regarding food use in chemistry was correct in
this assumption based on observations of student interest
through this unit. This unit was designed to encourage
student learning by incorporating nine more food based labs
that were developed for this research project.

41

The biggest challenge in implementing this unit was
the time crunch that ensued by trying to get in nine labs
Over a two week time period. This crunch was not only on
material being covered but on the instructor, due to set up
and break down of labs every day. Students were very
excited to be engaged in lab activities at the start of the
unit. As it progressed, some students began to feel
overwhelmed by the large number of labs in such a short
time frame. This was evident to me through observations of
student behavior. By the end of the two weeks students
were not as focused on accuracy and precision and more on
simply finishing the lab.

If I were to engage in another formal study of this
topic I might have explained each lab and notes before
doing hands on work and then had them take the pre test.
This would indicate how much the lecture portion affected
scores and then they could have taken the post test after
the labs to determine their increase in knowledge. That
would have shown how large a role the labs really had or if
they were just fun for them. As for changes in particular
labs, I would probably remove the strawberry lab from
future iterations of this unit. It is hard to explain the
chemistry and biochemistry involved in this activity for

42

such young students with limited interest. That is part of
the reason that when developing this activity it was
simplified a great deal. In the next teaching of this unit
I will try different types of “happy meals” such as chicken
nuggets in the McMush lab. The burger in the meal makes
the blended mush very dark and difficult to get good
colorimetric results with the indicators used. The Vitamin
C lab functions well in its current form and is a good lab
for practicing titrations. The Ice Cream Lab also met
instructional goals and worked well. I might, however,
move the soda lab ahead of other labs in the unit so that
we could use the product with our ice cream. The M & M ®
lab worked well, although students need to make sure they
put a large concentrated dot on their sheet to get good
results. Lastly, the Jell-O ® lab worked well. However I
will have the students explore the effects of acidity and
temperature on enzyme function when I use it again. This
is an aspect that could be incorporated fairly easily
through the use of buffers and water baths.

Based on the data presented in the pre and post test
assessments and the post unit surveys, I believe that by
implementing the food chemistry unit student comprehension
of related concepts and ideas increased. This makes the

43

development and implementation of this unit a worthwhile
addition to Chemistry B. My objective for developing this
unit as well as meeting the instructional goals was

achieved.

44

APPENDIX.A
CONSENT-ASSENT FORMS
Using Food to Engage Learning in Chemistry
Parent Consent and Student Assent Form

I am currently enrolled as a graduate student in Michigan
State University’s Department of Science and Mathematics

Education (DSME). My thesis research is on the use of food
to improve student understanding of a variety of chemistry
concepts. Some components will involve looking at food as

not only something to eat but the wide range of chemistry
that is involved in its composition as well as the making
of food to show various chemical reactions.

Data for the study will be collected from standard student
work generated in the course of teaching this unit such as
pre and post tests, lab activities, quizzes, and surveys.

I am asking for your permission to include your child’s
data in my thesis. Your child’s privacy is a foremost
concern. During the study, I will collect and copy student
work. These assignments will have the student’s name
removed prior to use in the study. All of the work being
collected will be stored in a locked drawer until my thesis
is finished and will be shredded at that time. In
addition, your child’s identity will not be attached to any
data in my thesis paper of in any images used in the thesis
presentation. Your child’s privacy will be protected to
the maximum extent allowable by law.

Participation in the study is completely voluntary.
Students who do not participate in the study will not be
penalized in any way. Students who do not participate in
the study will still be expected to participate in class
and complete all assignments. Students who do participate
in the study will not be given extra work to complete. You
may request that your child's information not be included
in this study at any time and your request will be honored.
There are no known risks associated with participating in
this study. Participation in this study may contribute to
determining if using food to teach chemistry will increase
chemistry comprehension in high school students.

45

If you are willing to allow your child to participate in
the study please complete the attached form and return it
to me by April 1St 2010. Please seal it in the provided
envelope with your child’s name on the outside of the
envelope. The envelopes will be stored in a locked drawer
and opened after the unit is completed. Any work from a
student who is not to be included in the study will be
shredded.

If you have any questions about the study, please contact
me by e-mail at briant@oe.edzone.net or by phone at (989)
834-2271. Questions about the study may also be directed
to Dr. Merle Heidemann at the DSME by email at
heidema2@msu.edu, by phone at (517) 432—2152, or by mail at
118 North Kedzie, East Lansing, Michigan 48824. If you
have any questions or concerns regarding your rights as a
study participant, or are dissatisfied at any time with any
aspect of this study, you may contact - anonymously, if you
wish — Peter Vasilenko, Ph.D., Director of the Human
Subject Protection Programs at Michigan State University,
by phone at (517) 355-2180, by email at irb@msu.edu, by fax
at (517) 432-4503, or by mail at 202 Olds Hall, East
Lansing, MI 48824.

 

 

 

Thank You,

Mr. Brian Topping
Chemistry Teacher
Ovid-Elsie High School

46

Parent Consent

I voluntarily agree to allow to
participate in this study. (print student name)

 

Please check all that apply:

I give Mr. Topping permission to use data generated
from my child’s work in chemistry class to be used in the
thesis project. All data from my child will remain
confidential.

I do not wish to have my child's work used in this
thesis project. I acknowledge that my child’s work will be
graded in the same manner regardless of participation in
the study.

I give Mr. Topping permission to use pictures of my
child during his work on this thesis project. My child
will not be identified in these pictures.

I do not wish to have my child’s picture used at any
time during this thesis project.

 

 

(Parent/Guardian signature) (date)

47

Student Assent
Please check all that apply:

I give Mr. Topping permission to use data generated
from my child’s work in chemistry class to be used in the
thesis project. All data from my child will remain
confidential.

I do not wish to have my child’s work used in this
thesis project. I acknowledge that my child’s work will be
graded in the same manner regardless of participation in
the study.

I give Mr. Topping permission to use pictures of my
child during his work on this thesis project. My child
will not be identified in these pictures.

I do not wish to have my child’s picture used at any

time during this thesis project.

I voluntarily agree to participate in this thesis project.

 

(Student signature) (date)

48

APPENDIX B

.Assessment Questions

I” What is a hydrocarbon?

2.How do we name hydrocarbons?

3.Explain what a functional group is and give a couple of
examples.

4.What is a calorimeter? If it helps you may draw a
picture.

5. How does a calorimeter work?

1.Name the major molecules of food and the tests can we
use to test for them.

'7.What is an ester?

8. Do you think a McDonald’s meal is a balanced source of
nutrients? Explain (name molecules).

9.What is an enzyme?

49

10. Describe how an enzyme works/function and give an
example.

11. When making homemade ice cream you add salt to ice.
What conditions does this create and why?

12. When we make homemade pop you need to add yeast to
the mixture. What function does the yeast serve and
why do we need to stop the reaction after only a few
days?

13.Some drinks have more vitamin C than others. How could
the amount of vitamin C be determined in each drink?
How much should we have in our diets/day?

14. Define and explain the process of chromatography?

50

APPENDIX C

Chemistry Survey
Rate the following questions on a scale from 1-5.
1 — Strongly Disagree

2 — Disagree

3 — Neutral/No opinion

4 - Agree

5 - Strongly Agree
1. Chemistry relates to everyday materials.

5 4 3 2 1
2. Chemistry can be better understood if it relates to
everyday things.

5 4 3 2 1
3. Chemistry courses should offer lab activities that
relate to everyday materials.

5 4 3 2 1
4. Chemistry courses should offer more lab activities
overall.

5 4 3 2 1
5. Lectures and labs are connected.

5 4 3 2 1
6. Chemistry labs have increased my understanding of the
content matter.

5 4 3 2 1
7. I learn more through lab than lecture.

5 4 3 2 1
8. Labs have increased my interest in science.

5 4 3 2 l
9. The best experiments are those that are very structured
and already written out for me to
follow.

5 4 3 2 1

10. I like labs that are open ended and allow me to test
many things.

5 4 3 2 l
11. I prefer working in groups in the lab.

5 4 3 2 1
12. I prefer working individually in the lab.

5 4 3 2 1
13. I am more focused on lab work if I know I will be
tested on it.

5 4 3 2 1
14. I am able to remember concepts when I have performed a
related experiment.

5 4 3 2 1

51

15. Experiments are more work than they are worth.

5 4 3 2 1
16. Briefly explain the basic chemical principles each of
the following labs:

Vitamin C lab:

Calories in Nuts:

McMush Lab:

Root beer lab:

Pineapple Jell-O Lab:

Strawberry DNA:

Ester Lab:

Ice Cream Lab:

Candy Chromatography:

17. Which lab helped you learn a particular concept the
most and why?

18. Did the use of food help you in learning chemistry
concepts? Explain.

19. What lab was not useful in helping you learn the
concept and why?

20. Would you like to have learned about another aspect of
food science that we did not cover? If yes what topic?

52

APPENDIX DI
Nut Lab

Objective
To determine the Calories in a variety of different nuts.

Introduction
When we eat food, our bodies convert the stored energy,
known as Calories, to chemical energy, thereby allowing us
to do work. A calorie is the amount of heat (energy)
required to raise the temperature of 1 gram (g) of water 1
degree Celsius (°C). The density of water is 1 gram per
milliliter (lg/ml) therefore 1 g of water is equal to 1 ml
of water. When we talk about caloric values of food, we
refer to them as Calories (notice the capital “C”), which
are actually kilocalories. There are 1000 calories in a
kilocalorie. So in reality, a food item that is listed as
having 10 Calories has 10,000 calories. Calories are a way
to measure the energy you get from the food you eat.
For this lab exercise, you will indirectly measure the
amount of Calories in couple of food items using a homemade
calorimeter. A calorimeter is a device that measures the
heat generated by a chemical reaction, change of state, or
formation of a solution. There are several types of
calorimeters but the main emphasis of all calorimeters is
to insulate the reaction to prevent heat loss. By measuring
the change in temperature (AT) of a known volume of water,
you will be able to calculate the amount of energy in the
food tested because the heat gained by the water will equal
the heat lost by the food item:
Qlost by food = anined by water
The energy gained by the water can be calculated as
follows:
Qwater = (m) I (AT)

where Q is the heat gained in calories (cal); m is the mass
of water in grams (g); c is the specific heat capacity of
water (1 calorie/g °C); and AT is the change in temperature
in degrees Celsius (°C).

53

Materials :

Ring Stand

Clay Triangle

Graduated cylinder

Water bottle with distilled water
Coffee can or beaker

Cork or Styrofoam with wire attached
Thermometer (in °C)

Lighter

Safety glasses

Materials in lab:

Cashews

Peanuts

Almonds

Walnuts

Popcorn

Scale

CAUTION!!! Flames will be used and items may be
hot!
All long hair must be tied back.

Procedure

1. 0f the 5 types of nuts you will be testing, hypothesize
which one will have more Calories (energy) per gram. Record
your prediction.

2. Obtain a weigh boat and determine its weight. Record
your data.

3. Obtain a sample of each nut and using the same weigh-
boat, determine the weight of the each. Record your data.
4. Using the graduated cylinder, measure out 100 ml of
distilled water from the water bottle and pour it into the
small metal can or beaker.

5. Measure the initial temperature of the water (Ti). Record
your data.

54

6. Gently wrap the wire attached to the cork or Styrofoam
around the nut. It is better to have the nut at a slight
angle. If it breaks, use another one; however, you will
have to reweigh the new sample.

7. Place the cork with the nut on a nonflammable surface.
Put on your safety glasses and light the nut. It may take a
while for the nut to catch on fire.

8. Then carefully balance the small can or beaker with
water on the ring stand.

9. Allow the nut to burn until it goes out. If possible try
to keep an eye on it and if it goes out quickly (less than
a minute), relight the nut.

10. Once the nut has finished burning, carefully remove the
small can or beaker. Caution! The cans or beakers and water
will be warm!

11. Using the thermometer, carefully stir the water and
then measure the temperature again (Tr). You may have to
leave the thermometer in the water for a while in order to
get the highest reading. Record your data.

12. Calculate the change in energy of the water (Q). This
is the same as the change in energy of the nut. Divide by
the mass of the nut and you have the energy per gram.

Make a lab report with a data table and all calculations.
Be sure to show all work. Also in your conclusion discuss
the following questions:
J” Are your numbers reasonable? Why or why not. If they
seem off what reasoning can you give as to why?
2. Possible errors made.
:2.What is it in the nut that gives us the energy?

55

APPENDIX DII
Scratch ‘n Sniff Ester
Lab Activity
Taken Pram: Source unknown

Materials

0 5 test tubes

0 Stirring rod

0 Hot plate (or ring stand, burner, and wire screen)
0 Boiling stone (if available)

0 150 mL Beaker

- Eyedropper or pipette

- 10 mL graduated cylinder

- Evaporating dish

- 5 card pieces

Safety Guidelines:

1. Put on your safety goggles and wear them until
everyone has finished the lab and the chemicals are put
away. ,

2. Be extremely careful with the concentrated sulfuric
acid. It can cause serious chemical burns.

3. Never smell the odors directly, use the wafting method
demonstrated during the pre—lab.

Procedure:

1. Prepare the hot water bath as outlined below:
a.Eill the 150 mL beaker with 75 mL of water and add
the boiling stone.
fl Set the beaker on the hot plate and bring the water
to a gentle boil.

x} If you are using a ring stand place the wire mesh on
the ring, then place the beaker on top. Light the
burner, adjusting the flame to an appropriate height
and temperature, and place underneath.

2.1abel 5 test tubes A to E.

3.Have your partner stay by the water bath while you go to

the chemical bench.

56

4.Using the appropriate eye droppers, add 10 drops of each
alcohol to the test tubes as outlined in the observation
data table. Waft the air towards you as demonstrated and
record the odors.

.5.You stay by the water bath and have your partner record
the odors of the carboxylic acids before they add 5
drops of each acid to the appropriate test tube (refer
to the observation data table).

6.Carefully mix the substances, rinsing the stirring rod

between test tubes.

'7.VERY CAREFULLY add 4 drops of concentrated sulfuric acid
to test tubes B, C, D, and E. Do not add any to test
tube A.

EL Carefully mix the substances, rinsing the stirring rod

between test tubes.
9.Place the test tubes in the water bath for approximately
5 minutes.

10. Label 5 cards with the names and formulas of the
resulting esters. Include their accompanying letter from
the observation table.

11. Remove the test tubes from the hot water bath.

12. Add 10 mL of cold water to the evaporating dish and
pour in the contents of one test tube, gently swirling
to mix the solution. Waft the air towards you and record
the odors.

13. Using the pipette place two drops on the appropriate

card.

14. Rinse out the pipette and evaporating dish and repeat
for each test tube.

15. Coat the smelly cards with gelatin and put in the
fridge to set.

16. Once set, scratch the cards with something sharp to
release the scent.

57

Observation Data Table:

 

 

 

 

 

 

 

Test Tube Alcohol Odor Car:::§lic Odor' Ester Odor
.A ISOpentyl Acetic
no Alcohol Acid
sulfuric (3-methyl- (ethanoic
acid l-butanol) acid)
Isopentyl Acetic
B Alcohol Acid
(3—methyl- (ethanoic
l-butanol) acid)
Isobutyl
C alcohol Propanoic
(2-methyl- Acid
1-butanol)
Ethyl SEEZnOic
D Alcohol .
(ethanol) (Butyric
Ac1d)
Methyl . .
E Alcohol iiiécyllc
(methanol)

 

 

 

 

 

 

 

General Observations:

58

 

Scratch ‘n Sniff Ester
Lab‘Write-Qp

When you have completed the lab activity and have cleaned
your workstation you may begin working on your lab write
up. Only one write-up needs to be submitted per workgroup.

1.'Title Page including:
a.1eb name
kL Partner’s name(s)
c. Date

2. Pre—lab worksheet individually completed by each
workgroup member

3.Summary that includes a:

a.
b.

Brief summary of Scratch ‘n Sniff stickers.
Comparison between Sticker A and the other
stickers.

. Comparison of how well your stickers worked to

how well you expected them to.

.Comparison between the odor of the products in

the evaporating dish and as stickers.

. Comparison between the odor of the reactants and

products.

4.Questions

a.

b.

What is the purpose of Test Tube A? Is sulfuric
acid (Hfiflh) included in the products?

Was there a reaction in test tube A? How do you
know?

.Why did we put the test tubes in a hot water

bath?

. If you were to redo the lab, what would you do

differently?

. In some cases the odor of the synthesized ester

does not exactly match the odor of the fragrance
found in nature. What might be a possible
explanation?

59

APPENDIX DIII

Measurement of Vitamin C in Fruit Juices
Adapted from Stephen Fuller

Introduction:

Vitamin C, also known as ascorbic acid is a necessity
for the human body. In this lab you will use your
knowledge of titrations to calculate the amount of vitamin
C in a variety of different fruit juices. We will use
iodine solution as our titration solution and starch as the
end-point indicator. As the ascorbic acid reacts with the
iodine it gets oxidized and the iodine is reduced. Reduced
iodine can't react with starch. Thus the titration will not
come to completion until the all the ascorbic acid has
reacted and a purple color will appear.

Purpose:

To test the concentrations of vitamin C in a variety
of different fruits or juices to see which variety has the
greatest concentration of vitamin C.

Materials :

Fruit Juices (apple, orange, grape) from concentrate
Vitamin C standard solution (from Vit C tablet) (1mg/mL)
Starch solution (1%)

Iodine Solution

Hydrochloric acid 1M

Distilled water

50 mL burette

Ring stand and burette clamp

Graduated cylinders

Erlenmeyer flasks

Beakers

Preparing Solutions:

Vitamin C Standard:
Dissolve 1 vitamin C tablet into distilled water. 1mL
of water for each mg of vitamin C present.

Starch Solution:

Mix 2 teaspoon of soluble starch (cornstarch or potato
starch) with 100 mL of distilled water and heat until it
dissolves. Be careful not to heat to a boil.

6O

Iodine Mixture :

Dissolve 0.6g of potassium iodide (KI) in 500 mL of
distilled water. Then dissolve 0.6g of iodine crystals (12)
in 50 mL of ethanol. Mix the two solutions together and
dilute until final volume is 1.0L.

Hydrochloric acid:
This solution will already be prepared for you due to
the danger of concentrated acid!

Procedure:
l.Using a graduated cylinder obtain 10 mL of the vitamin
C standard you prepared and place it in a 250 mL
Erlenmeyer flask. Then add 20 mL of distilled water.
This simply helps to see the reaction; water does not
react in this experiment.

12.Add 2 drops of the 1M HCl and 15 drops of starch
solution to the vitamin C standard.

3. Fill a 50 mL burette with iodine solution and record
the initial volume on the burette.

4. Place the flask containing the standard sample under
the burette and begin your titration. Be sure to use
the techniques we used when doing titrations to ensure
you don’t add to much iodine. Once you have a slight
purple color your titration is finished. Record the
final volume.

5.Repeat 2 more times to get an average amount used.

6.Using a clean 10 mL graduated cylinder repeat the
above procedure but instead of using 10 mL of the
vitamin C standard use the fruit juice samples made
according to the directions on the can. 3 trails for
each type of fruit juice.

Data:
Include all data in your lab report. Show all

calculations!!!
61

Calculations:

3.

Calculate the volume of iodine solution used for each
trial.

. Find the average of each sample. (Add volumes from 3

trials and divide by 3)

.Using proportions we can calculate the amount of

Vitamin C in your fruit juices. To do this you can
use the following formula:

X mg = (average iodine used for fruit juice (mm) (10 39).
Average iodine used for the standard solution (mL)

. Based on your calculations which juice contained the

most vitamin C?

. The minimum daily requirements (US RDA) for vitamin C

are 60 mg/day. How much of your juice would you need
to drink to get your 60 mg/day?

62

APPENDIX DIV

McMush Lab

Adapted From: various Sources

Overview

Everything you eat is composed of three major
components: carbohydrates, proteins, and fats. The cells in
all living things contain these macromolecules as well as
nucleic acids and inorganic compounds such as vitamins and
minerals.

In order to release energy from food, the body must be
able to break the food into these basic compounds and then
further reduce them to the molecular level. The body can
absorb food only when it is at the molecular level.

Carbohydrates are a source of “quick” energy for the
body. The building blocks of carbohydrates are simple
sugars like glucose. Starches are carbohydrates known as
polysaccharides. Polysaccharides or starches are stored by
plants for an energy reserve and are formed when many
single sugars are joined together. A single starch
molecule consists of hundreds of glucose molecules.

The building blocks of proteins are amino acids. In
order for your body to manufacture the specific proteins it
needs, the protein eaten in the diet must be broken down
into amino acids ready for reassembly into proteins.

Fats (lipids) are important to your body because they
are used to make up part of the cell membrane. Ingested
fats provide the raw materials for making our own fats and
cholesterol. Cholesterol is essential for making the
steroid hormones such as testosterone, estrogen, and
progesterone.

In addition to the organic compounds, the human body
needs minerals and vitamins. One mineral needed is sodium
chloride or table salt. Sodium is the main component of the
body’s extra cellular fluids and it helps carry nutrients
into the cells. Sodium also helps regulate other body
functions, such as blood pressure and fluid volume. A
Vitamin needed in the human diet is Vitamin C. Vitamin C
(Ascorbic acid) is a vitamin that functions in the
synthesis of collagen (essential component of bones, skin,
tendons, etc). It is found in citrus fruits. A deficiency
of Vitamin C results in scurvy.

63

Materials

Per Group

8 test tubes - Paper towels
McMush solution beaker for distilled
water
Tube Rack 2 beakers for McMush
solution
filter paper ' test—tube clamp
distilled water - Pipets

' Cheese Cloth
Chemicals for Tests
Sudan III Fat Stain ' Lugol's Iodine (IKI)
Bradford's Solution - Indophenol Solution

Benedict's Solution
Silver Nitrate
Solution

Procedure

' Your instructor will perform several tests (controls)
using various reagents. Record the results of these
tests in Table 1.

° In Table 2, predict the results of each test that will

be done. Use‘+ for a positive result and - for a
negative result. Record your test results.

° Your instructor will perform the control tests using
water. Record these results in Table 2 after you make
your predictions.

CAUTION: The reagents you will.be using in
the following procedures.may be corrosive, poisonous,
and/or irritants; they may damage clothingu .Avoid
skin and eye contact. If contact occurs, notify'your
instructor.

Preliminary Procedures
1. Label the micro centrifuge tubes as follows:

C = carbohydrate G = glucose
P = protein V = vitamin C
L = lipid S = salt

64

2. Add 12 drops of the McMush solution to each tube.
3. Add the appropriate reagent to the micro centrifuge
tube to test for each of the organic and inorganic
compounds.

4. I will do the water tubes on Day 2.
BE VERY SURE THE LIBS OF THE TUBES.ARE
SNAPRED ON TIGHTLY.RRIOR TO.MIXING
' CARBOHYDRATE: Add 2—4 drops of IKI to tube C. The
solution will turn from yellow-gold to blue—black
if a carbohydrate (specifically starch) is
present.

° PROTEIN: Add 10-15 drops of Bradford’s solution
to tube P. The solution will turn from red to
purple if a protein is present.

° LIPID: Add 5 drops of Sudan III to tube L and mix
vigorously. The solution will turn pale yellow if
no lipids are present. It will make two layers if
lipids are present. The top layer containing the
lipid will be pale pink to orange. To quantify
amount of lipids add 100 mL of McMush to a 500 mL
beaker. Boil for 15 minutes, be sure it doesn’t
boil over. Then put into refridgerator
overnight. The next day calculate the percent
lipids by volume. The lipids will be found on
the top layer.

' GLUCOSE: Add 12 drops of Benedict’s solution to
the G tube. Swirl to mix and place into hot water
bath for 5 minutes or so. The blue solution will
turn orange-yellow if glucose is present. BE VERY
CAREFULL REMOVING THE TUBE EROM’THE HOT HATER.
USE PROPER SAFETY EQUIPMENT.

° ‘VITAMIN C: Add 1-2 drops of indophenol solution
to tube V. The indophenol will turn colorless if
Vitamin C is present in the solution. Ignore the
intermediate pink stage.

65

° SODIUM CHLORIDE: Add 6 drops of Silver nitrate to
tube S. Silver nitrate forms a white precipitate
when added to sodium chloride.

Part E: Clean-up

>

Discard all used tubes and pipets in designated
container. Place clean tubes in basket for next
class.

Put clean pipets in basket.

Wash the beakers with soapy water, rinse and place in
basket.

Put the basket (clean and ready for next class) back
on the prep table.

Wash your table with a soapy cloth to remove any
harmful chemicals.

Complete the lab report and turn in as soon as you are
finished.

66

Data :

McMush Laboratory Report

Table 1 - Reagent Tests of Known Organic Compounds

 

 

 

 

 

 

 

 

Mineral Oil

Organic Food Reagent Positive
Compound Appearance Appearance Test
before Before Result
Food Tested Reagent Testing Testing Color
Carbohydrate
I
(Starch) Lugol 5
Corn Starch Solution
. IKI
Solution
Protein
_ Bradford
Gelatin Solution
Lipid
Sudan III
Solution

 

 

 

 

 

 

 

 

Glucose
Benedict's
Solution
Glucose Soln
Vitamin C
Indophenol
Citric Acid
Sodium
Chlor'de .
1 Silver
Nitrate
Salt H20

 

 

 

 

 

 

 

67

 

Table 2 - Analysis of Organic Compounds in McMush

Predict if McMush and water (control) will contain any of
the compounds in the table. Use'+ for YES and - for
NO. Test the McMush and use +'for a positive result

and'- for a negative result.

 

CARB PROTEIN LIPID GLUCOSE ‘VITAMIN SODIUM

 

 

 

 

 

 

 

 

 

 

 

C CHLORIDE
Tube C W P W L W G W V W S W
Prediction
Results

 

 

 

 

 

 

 

Analysis of Results:

l.Summarize how effectively you were able to predict the
results of these tests.

22.Were you surprised by the results of any of your tests?
Explain.

3.What was the control for your tests? Why did you use
this control?

4.The instructor performed a series of tests at the
beginning of class. Why?

68

5.What organic and inorganic components were present in
the McMush solution?

6.Which parts of the Happy Meal probably contained these
compounds?

'7.What possible errors might have occurred in this lab and
why? Be sure to talk about the analysis of fat/lipid
content.

69

.APPENDIX DV
HOMEMADE SODA LAB
Mbdified from: David B. Fankhauser

Introduction:

Fermentation has been used for thousands of years for
raising bread, fermenting wine, and brewing beer. The
products of the fermentation of sugar by baker’s or brewing
yeast Saccharomyces cerevisiae (a fungus) are ethyl alcohol
and carbon dioxide. Carbon dioxide causes bread to rise and
gives effervescent drinks their bubbles. This action of
yeast on sugar is used to ‘carbonate’ beverages.

Materials:

clean 2 liter plastic soft drink bottle with cap.
funnel

measuring cup

1/8 tsp measuring spoon

1 Tbl measuring spoon

1 cup table sugar

* Root beer extract or other soda flavoring (can be
purchased at Michigan Brewing Co.)

* Brewing or Baking Yeast

* Water

I'i-X-I-X-i-

Procedure:

1. Add 1 to 1.5 cups of sugar to your 2 liter bottle using
your funnel.

2. Dissolve 1/8 of a tsp of yeast in some warm water in
your measuring cup.

3. Add 1 tbl spoon of your root beer or soda flavoring to
the 2 liter bottle and sugar.

4. Fill 2 liter bottle % of the way up with water and
shake to dissolve the sugar.

5. Add your yeast solution to the bottle and top off with
water leaving only a small pocket of air (about .5 inches).

6. Place bottle in a box so that if it explodes the mess
will be contained. Check daily to ensure the pressure

isn't getting to great

70

EL Once bottle has reached a pressure that the bottle feels
stiff place in the refrigerator for 2 weeks to slow/kill
‘off the yeast. This will ensure a better flavor.

Data:

Write a lab report on this lab. Be sure to include the

reaction occurring in the bottle as well as time required
for each step.

71

APPENDIX DVI
DNA Extraction: Strawberry
Taken From: Science Behind Our Food

Background:

The long, thick fibers of DNA store the information
for the functioning of the chemistry of life. DNA is
present in every cell of plants and animals. The DNA found
in strawberry cells can be extracted using common, everyday
materials. We will use an extraction buffer containing
salt, to break up protein chains that bind around the
nucleic acids, and dish soap to dissolve the lipid (fat)
part of the strawberry cell wall and nuclear membrane. This
extraction buffer will help provide us access to the DNA
inside the cells.

Pre-lab questions:
1. What do you think the DNA will look like?

2. Where is DNA found?

Materials :

heavy duty Ziploc bag

1 strawberry

10 mL DNA extraction buffer (lml soap, 1ml salt, 8ml water)
cheesecloth

funnel for filtering

50mL vial / test tube

glass rod, inoculating loop, or popsicle stick

20 mL ethanol (cold)

Procedure:
1. Place one strawberry in a Ziploc bag.
2. Smash/grind up the strawberry using your fist and
fingers for 2 minutes. Careful not to break the bag!!
3. Add the provided 10mL of extraction buffer (salt and
soap solution) to the bag.
4. Kneed/mush the strawberry in the bag again for 1 minute.
5. Assemble your filtration apparatus with cheesecloth over
the funnel.
6. Pour the strawberry slurry into the filtration apparatus
and let it drip directly into your test tube.
7. Slowly pour cold ethanol into the tube. OBSERVE
8. Dip the loop or glass rod into the tube where the
strawberry extract and ethanol layers come into contact
with each other. OBSERVE

72

Conclusions and.Analysis

9.It is important that you understand the steps in the
extraction procedure and why each step was necessary.
Each step in the procedure aided in isolating the DNA
from other cellular materials.

Match the procedure with its function:

PROCEDURE FUNCTION

A. Filter strawberry slurry through cheesecloth ___ To
precipitate DNA from
solution

B. Mush strawberry with salty/soapy solution ___ Separate
components of the cell

C. Initial smashing and grinding of strawberry ___ Break
open the cells

D. Addition of ethanol to filtered extract Break up

proteins and dissolve
cell membranes

2. What did the DNA look like? Relate what you know about
the chemical structure of DNA to what you observed today.

3. Explain what happened in the final step when you added
ethanol to your strawberry extract. (Hint: DNA is soluble
in water, but not in ethanol)

4. A person cannot see a single cotton thread 100 feet
away, but if you wound thousands of threads together into a
rope, it would be visible much further away. Is this
statement analogous to our DNA extraction? Explain.

5. Why is it important for scientists to be able to remove
DNA from an organism? List two reasons.

10. Is there DNA in your food? How do you know?

73

APPENDIX DVII
Jell-O Lab

Jell-O consists of proteins called collagen. Collagen
is a triple helix protein found in animals. Collagen’s
main function is a major component of connective tissue in
the skin and provide a framework for various organs (holds
them in place). When you make Jell-O you need to add hot
water to dissolve the collagen protein molecules. Under
heat the three stranded protein unwraps. As it cools,
water is trapped between the strands forming a gel like
substance. You can think of it like spaghetti noodles
hardening up on a plate trapping molecules between them.
We need many kinds of proteins to survive and each has a
different function but for this lab we will only look at
collagen.

Enzymes are often called biological catalysts. They
help speed up bodily processes and remove or break down
certain toxins such as alcohol as well as many other
functions. Enzymes themselves are almost always proteins.
For example when you chew your food your body makes an
enzyme called amylase to assist in the break down of
starches (complex sugars). It gives the body a head start
to the digestion process. Plants also make enzymes. One
that we will look at is Bromelain. This a protein made by
many tropical fruits such as pineapple and kiwi. It is an
enzyme that breaks down collagen. This makes pineapple a
very good meat tenderizer.

Materials needed:

1 box of Jell—O or Gelatin
1 can of pineapple

1 fresh pineapple

2 bowls

Procedure:

Make your box of Jell-O or gelatin according to the
directions on the box and then evenly split the amount of
Jell-O into the two bowls.

To one of the bowls add the canned pineapple.

To the other add the fresh pineapple.

Store in the fridge over night for observation tomorrow.

You need to write summary of your results. Be sure to
explain what happened in the two bowls. Include possible
errors.

74

APPENDIX DVIII
Chromatography Candies with Compared to
Reese’s Pieces of M & M®

Adapted from: Various Sources
Introduction

Colors in candies are due to synthetic dyes that have been
approved by the Food and Drug Administration (FDA).
Sometimes the colors, such as greens and browns are
mixtures of several dyes. In this laboratory we will
separate the colors in M & M® candies and Reese’s Pieces®
by means of paper chromatography. Differences in the
molecular size and solubility of the dyes will enable us to
make the separation. The smaller, more soluble dyes, will
travel up the paper faster than dyes that are less soluble
and larger.

Purpose

To determine if the brown coloring matter in M & M® candies
is the same as the brown coloring matter in Reese’s
Pieces®, at the same time, other candy colors will be
chromatographed to determine their component colors.

Safety

1. Wear protective goggles throughout the laboratory
activity.

2. Do not eat any of the candy used in the laboratory
activity.

Procedure

1. Obtain 3-4 brown M & M® candies. Place them in a
small evaporating dish and place a few drops of tap water
on them. Stir around with a toothpick to extract the color.
As soon as the colored layer is extracted, remove the
pieces from the dish with forceps and discard them. Be
careful not to extract the candy too much because you don't
want any of the chocolate in the solution.

2. Repeat with some brown Reese’s Pieces® in a second
evaporating dish. Use clean toothpicks for each dish.

75

3. Obtain a piece of chromatography paper that will
accommodate spots of both candy colors. Cut it into a 5”x5”
square if it is not already done for you. Draw a light
pencil (DON’T USE PEN!!!) line about 3 cm from the bottom
edge of the paper and initial the paper in one upper
corner. Put pencil dots on the original pencil line, about
3 cm apart. Label each as M & M® and Reese’s Pieces as well
as the initial color of the dye.

4. Using small capillary tubes place spots of each
color on the labeled dot. The spots should be about 1 cm in
diameter, and must not overlap. Let dry and apply more
sample, keeping the spots as small as possible. Repeat
until you have placed about 5-6 spots on each dot to make a
concentrated sample.

5. Obtain the proper container for the chromatography
(beaker or jar) and pour in a 1M NaCl solution until it is
about 1 cm deep. Fold the paper so it will stand up on it
own in the beaker. Be sure that the lower end of the paper
is just touching the solution, and that the solution does
not reach the colored spots.

6. When the solution rises to within 3 cm of the top of
the paper, remove the paper from the solution and allow it
to dry. Mark the position of the solution on the paper with
a light pencil line.

7. Compare the chromatograms for each dye to determine
if the candies contain the same dyes.

8. Thoroughly wash your hands before leaving the
laboratory.

76

Data Analysis and Concept Development

Notice the number and colors of the spots on the two
chromatograms. Draw circles around the spots that are
common to the two candies. The spots must be the same color
and must have traveled the same distance up the paper.

1. Is a pure brown dye used to color the candies?

2. If you wished to produce a green dye, what colors
would you use?

3. Suppose you were given an unmarked bag of one of
these candies. How could you distinguish chemically whether
the contents were M & M's® or Reese’s Pieces®?

Implications and.Applications
1. How could chromatography be used to distinguish some

look-alike candies?

2. How could you tell which dyes were present in the
candies?

77

APPENDIX DIX
Ice Cream.Lab

Background

Colligative properties depend on the number of particles
dissolved in a given mass of solvent. Three types of
colligative properties are vapor-pressure lowering,
boiling-point elevation, and freezing-point depression.
This lab will focus on freezing-point depression. The
freezing point is the temperature at which there is an
equilibrium between the solid and liquid phases of a
substance. The temperature when this occurs is specific for
different substances. The freezing point depression is the
difference in temperature between the freezing point of a
solution and that of the pure solvent. The presence of a
solute (salt) in water disrupts the formation of the solid
ice crystals thus lowering the freezing point. You will use
freezing-point depression to make ice cream.

Procedure

1. Each person will make a baggie (snack size, Ziploc
brand) of ice cream; you will put 2 or 3 baggies in one big
bag (gallon size freezer bags work best, any brand). I will
have measured out a 8 cup milk, 1 tablespoon sugar, and M
teaspoon vanilla into a small bag and zip it (make sure it
is sealed well).

2. Take the large bag and fill it with 2 or 3 scoops of ice
cubes. Add 2 small scoops of rock salt.

3. Place the 2 or 3 small bags in the large bag; try to
spread them out a bit. Seal the large bag. Make sure the
small bags are still zipped; otherwise salt water will get
mixed with your ice cream and that won’t taste very good!

4. Shake gently for about 10-15 minutes or until the ice
cream inside begins to harden. It could take longer than
that however. Don’t give up! Continue to keep the ice
covering the small bag. IF YOUR SALT/WATER BAG BEGINS TO
LEAK HOLD IT OVER THE SINK. IF YOUR SALT/WATER BAG LEAKS,
THEN THROW IT AWAY AT THE END OF THE HOUR. SAVE SALT/WATER
BAGS THAT DO NOT LEAK!!

78

5. Open the large bag when your ice cream has hardened.
Take the temperature of the ice/salt solution. Record the
temperature.

6. Remove the small bags and rinse them off. Enjoy your ice
cream!!!!

7. Save the large bag and spoons. Throw away the small bag
when finished and clean up all your messes such as spilled
mild or dripped ice cream.

Pre-lab Questions

1. What is the purpose of this lab?

2. What is a colligative property (the definition)?

3. What are three important colligative properties
(examples)?

4. What will happen if you do not seal the inner bag
properly?

5. What will happen to the freezing point of water (ice)
after you put salt with it?

Data Table
temperature of ice/salt mixture =
Data Analysis

1. At what temperature does water normally freeze?

2. What was the temperature of the ice salt mixture?

79

3. Read this carefully. How does the freezing temperature
of water compare to the temperature of the ice/salt
mixture? (show both temperatures and compare)

4. Explain what has happened in the bag. What does the
sodium chloride do? (Do NOT tell me the freezing
temperature went down, tell me why!

5. Provide another example of when people use freezing-
point depression in real-life.

80

APPENDIX EI
STUDENT RESULTS PRE AND POST ASSESSMENT SCORES

Pre-test Post-test
Student Score Score

H
N

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oxoooxloxmanr—Iomcoqmme-wmh—J
H
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WWWWWNNNNNNNN
bWNHOkDCDQGUlubUJN

5
3
3
2
5
l
l
6
O
7
O
O
2
4
21 l
4
3
1
0
1
2
3
1
2
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6
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9

(A)
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81

APPENDIX EII
POST UNIT SURVEY RESULTS
6 10
4 4
4

1

_fi

1
1
1
1
1
1
1
1
1
1

N
_a

5
1 1 1 1 1
4.11 4.1 4 3. 3.31 3.31 3 3.91 4. 3.91 4

 

82

APPENDIX EIII
STUDENT RESULTS FOR EACH QUESTION PRE TEST

re

 

83

APPENDIX EIV
STUDENT POST TEST SCORES FOR EACH QUESTION

 

84

Appendix F - State Standards Covered (MDE)

C1.1C Conduct scientific investigations using
appropriate tools and techniques (e.g., selecting an
instrument that measures the desired quantity—length,
volume, weight, time interval, temperature—with the
appropriate level of precision).

C3.1C Calculate the AH for a chemical reaction using
simple coffee cup calorimetry.

C3.1X Hess’s Law

C4.2E Given the formula for a simple hydrocarbon, draw
and name the isomers.

C4.5A Provide macroscopic examples, atomic and molecular
explanations, and mathematical representations (graphs and

equations) for the pressure—volume relationship in gases.

C4.7A Investigate the difference in the boiling point or
freezing point of pure water and a salt solution.

C5.2A Balance simple chemical equations applying the
conservation of matter.

C5.7A Recognize formulas for common inorganic acids,
carboxylic acids, and bases formed from families I and II.

C5.8A Draw structural formulas for up to ten carbon
chains of simple hydrocarbons.

C5.8C Recognize that proteins, starches, and other large
biological molecules are polymers.

85

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