...‘: l.nr'.|.l.I fin bu: Alt 5... .uuhlbl o... I" q I... . . . ,. u. 51.6mm? 4.51 1. angswmw.fl C. Sun- . a. 09-3... .fimwn ii .4 .33 L . a . Hie-.2 .t Faintii ll. .. .211: 1 . . .t . .. 2 . D K oi..- MI. 5:! “up. 1? IL...» flbfls . It... ir . was... Kitt‘flll >751: . iii... .5 .\ c 0w“ y . —I A V. . A. '\ a u «i . firth-”fink .p..l!.u!: ai!'¢\ .14.z..ur.rfi£.fl: 3.50 2,335.13}! 1%.. s z $.45... a... ~ OHSW‘EE. flannel... . fiat .tl:_ .3... i. «.2!ch ..\.vdzllll! .13.:(1‘3 . .> It'lrlii I .k dual. Essa- . am lllllllllllllllllllllllllllllllllllllllllllllllllllllllllll 31293 02050 9927 o [.3319 .Ilisii'cgi , 4,0 “‘ m th‘vgruu This is to certify that the thesis entitled Cooperative Learning in the Chemisty ClaSsroom presented by Melissa Flynn has been accepted towards fulfillment of the requirements for MasLers—_degree in Science.— L 7 / a Major professor 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution PLACE IN RETURN BOX to remove this checkout from your record. To AVOID FINE return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE Fifi ~ "3- APR 3 o 2005 MAE § 1? glint in 1 :2. 0 4 11/00 WEE/0.03.9659.“ COOPERATIVE LEARNING IN THE CHEMISTRY CLASSROOM BY Melissa Ann Flynn A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF PHYSICAL SCIENCE Division of Science Education 1999 ABSTRACT COOPERATIVE LEARNING IN THE CHEMISTRY CLASSROOM BY Melissa Ann Flynn Research has attempted to provide educators with various techniques to increase student learning. Cooperative learning is one such technique, which encourages students to work together in order to better understand a problem. The purpose of this study was to incorporate cooperative learning into the chemistry classroom to see if students retained information better and thus had a better feeling toward science as well as themselves as learners. The addition of the cooperative learning techniques in the first semester of the course showed positive differences in student achievement when compared to the previous year. This study focused not only on students’ academic achievement, but their self-esteem as well. By using the cooperative learning process, students became more comfortable communicating with others and made them more secure in their abilities. The process also 3 involves a change in the teacher's role from lecturer to — .]~" M .-—.v' facilitator to organize groups and to encourage working a.” together. Different lessons and laboratory exercises had to be implemented for the program to work. This study used data from student tests as well as several surveys of the students as evaluative tools. The findings were that cooperative learning does increase the students’ understanding of the material, retention of knowledge, and makes them feel better about themselves and school. Dedicated to my husband Paul. Without his persistence and help this paper would still not be done today. iv List of Tables List of Figures Literature Review Statement of Problem and Rationale Implementation of Unit Evaluation Discussion TABLE OF CONTENTS .vii viii .10 & Appendix A: Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix B: C: Conclusion. Listening Activitym.mm. Pairs-Check Worksheet. OOOOOOOOOOOOOOOOOOOOOOOO Daily Lesson Plans Experiments Laboratory Investigations mm- Unit Test Results 70% or Better on Unit Tests Graphs of 70% or Better Science Survey: Question Set Science Survey: Question Set Science Survey: Question Set Science Survey: Question Set I Graphs ......... II II Graphs ...... Self-Test Survey Self-Test Survey Graphs 14 20 32 39 4O 49 75 100 114 115 116 120 121 129 130 142 143 Bibliography . 157 Table Table Table Table Table Table Table LIST OF TABLES Activities of Science Describing Matter Chemical Reactions and Equations Molar Relationships Stoichiometry Science Survey: Question Set I Science Survey: Question Set II fii Figure Figure Figure Figure Figure Scores Scores Scores Scores Scores LIST OF FIGURES for for for for for Activities of Science Describing Matter Chemical Reactions and Equations Molar Relationships Stoichiometry viii .. J J '1 I. Literature Review The purpose of any learning situation is to teach knowledge in a way that the student will most likely retain or master the information. Schools and teachers throughout history have assessed their instruction resulting in different theories of instruction. Many times these theories seem to fall by the wayside and instruction reverts back to what was easier for the teacher. The teaching strategy of cooperative learning has brought together many ideas and processes that are beneficial in the world of business. This strategy is simple enough that a teacher does not have to change their approach to teaching their curriculum in a drastic way. Cooperative learning evolved from the observations that the old way of working individually was not reaching the goal of all students learning. Retention of knowledge is more likely to occur when people work together to solve a problem or understand a new concept. Studies (Smith 1994) show that cooperative learning typically results in both immediate and long term benefits, greater personal growth by students, and closer interaction with students by the teacher and new role of teacher as facilitator. Karl Smith (1994) describes cooperation as “working p together to accomplish shared goals, while cooperative P "I Fla Bil n\~ «an learning is the instructional use of small groups so that students work together to maximize their own and others’ “ _‘ p“ m w “\Mpn=m-—_.n .....~..-.\W" "nu....-;_lm‘“~‘—M u " “' .Mrmvr. learning”. Successful cooperative learning requires “MW “‘“Aahun *,_~.,,._ . ' ”*m-— . implementation of several factors. Cooperation among students usually results in higher achievement and greater productivity, more support among learners, and a higher level of self-esteem. NomIonger can the teacher simply stand in front of a blackboard and regurgitate facts from a book. Every college teacher preparation program teaches that different students have different learning styles. Attention to individual styles on the part of the teacher leads to more mastery of the material. With a mastery goal, importance is attached to developing new skills. The process of learning itself is valued, and the attainment of mastery is seen as dependent on effort (Ames & Archer 1988). This is also viewed as task involvement, which according to Graham and Golan (1991) “one’s goal is to master the taskm in which greater understanding or acquisition of new skills is considered an end to itself”. Therefore, mastery goals increase the amount of time children spend on learning tasks and their persistence in the face of difficulty, but more importantly, the quality of their engagement in learning (Ames 1992; Butler 1987; Elliot & Dweck 1988). Cooperative learning allows each student to approach an assignment in a different way if needed. Ideally, it makes students more comfortable to ask questions, try new things, and support each other in their successes and failures. Ames and Archer (1988) state, “Although challenging tasks offer opportunities for learning, they also present the risk of failure, thereby threatening students’ sense of worth when failure is normatively defined. As a consequence, challenging tasks may be less threatening or more attractive to students who view the situation as emphasizing the process of learning, encouraging effortful activity, and de- emphasizing the negative consequences of making errors”. A student is more apt to see that he or she is not the only person who doesn’t completely understand a concept or a problem. Students are more likely to work harder when a peer, or a group of peers, is available to assist. In addition to mastery of the subject area, cooperative learning teaches students skills that they will be able to take with them beyond their school years. It builds on skills that students may not use if learning in the old style classroom where information is presented to the students and they work on problems individually without communication with other students. Deutsch (1962) and Johnson and Johnson (1989) state that in individualistic learning situations, students work alone to accomplish goals unrelated to those of classmates and are evaluated on the criterion-referenced basis. Students’ goal achievements are independent; students perceive that the achievement of their learning goals is unrelated to what other students do. The result is to focus on self-interest and personal success and ignore as irrelevant the successes and failures of others. TBy using cooperative learning, students have the opportunity to develop their leadership and social skills when working ‘in groups. The more socially skilled students are and the S\more attention instructors pay to teaching and rewarding the _ _.-,__.__,___.\‘/____.‘ use of social skills, the higher the achievement that can be expected from cooperative learning groups (Johnson, Johnson, and Smith 1991). The structure of group work lends itself to the need for a strong leader, as well as others taking responsibility for their roles. Each student must use their decision making and communication skills for the success of the group. -Individuals are not allowed to let others do all the work. There is an interdependence that is essential. w‘, ~--....__.., - .r—~\-r—--- As Smith (1994) states, i(a positive interdependence linked with others in a way that one cannot succeed unless the other members of the group succeed and vice versa”. Complications can arise in any cooperative interaction and with that students must deal with some conflict management skills. Johnson, Johnson, and Smith (1991) argue that when conflict arises, positive interdependence is structured by having each group arrive at a consensus, submit one written report, and make one presentation; by jigsawing the f l materials to the pairs within the group. It also is strengthened by giving bonus points to members if all members learn the basic information contained in the two positions and score well on the test. Individual accountability is structured by asking each member of the pair to participate orally in the group’s presentation, and by having each member take an individual test on the material. This interdependence also relies on the students’ ability to build a level of trust among the members of the group. Each and every one of these traits formed by this interdependence will help the student outside of the school atmosphere. .. Cooperative learning will also have a positive \ influence on the teacher of the subject area. Their role J an" ‘ fl”.- ‘bs \ ichanges from lecturer to that of facilitator. They are no longer a Ehreatening force to the meek or timid student, but ““ a»... "team-amt?“ . '39- a respected resource that these groups can access for clarification and guidance. Perhaps a more important role of the teacher is that they must become a motivator. It is important for a téééhér'to Show their students that there is some importance to learning the material and that it can be engaging. A study by Brophy, Rohrkemper, Rashid, and Goldberger (1983) shows a higher quality of student task engagement can be expected when students are working on 2 tasks that they enjoy or believe to be interesting or worthwhile than when they are working on tasks that they dislike or believe to be boring or pointless. Increasing students’ desires to learn for themselves can also raise the self-esteem and confidence of students. By retaining knowledge that they deem important, they will feel better about themselves as learners. Lack of motivation, however, can result in less learning and more management problems for the teacher. It is known that student aptitude is the greatest influence on student learning. However, studies show that different kinds of classroom instruction and climate have nearly as much impact as student aptitude. Classroom management, which includes group alerting, learner accountability, and teacher "with—it-ness", falls into this category according to Wang, Hertel, and Walberg (1994). James Sweeney (1992) lists the key beliefs and values that have a powerful influence on determining success in school. They are as follows: -Respect for the Individual -Self—esteem -Sense of Efficacy -Achievement Orientation -Collegiality -Trust -Caring These values and beliefs, or lack of, are what I believe is causing some of the students to do poorly. But my problem is how do I change these values and beliefs? Lee Morganett (1995) has shown that if a teacher were to improve the teacher-student relationship then these values and beliefs improve. One way to do this is to get to know the students’ names as quickly as possible. Students appreciate this. Another way is to get to know something personal about each student. Ask them their opinion to get them to participate and feel valued. Along a similar line, one could conduct a value analysis discussion about a current event. Make sure the rules are followed: Everyone listens to the speaker, any one can respond, but no one can directly disagree with one another. Provide positive comments when appropriate and avoid the use of threats. Teachers can recognize effort, and cooperative behavior. One can also make positive comments on a new hairstyle, a pair of shoes or maybe a shirt, but be sure the student will /\./k//"“‘ not be embarrassed. The comments could be made privately to ”1.....-“ ._ ..-, the student. Create a supportive classroom environment, one ,r ' Hm... . ..- 9 u r. n...— “’p‘-J'u,15.k'.‘. (- 'J .4- " ~.where questions and answers, even wrong answers, are valued. i i Have students work cooperatively and grade on both individual and group achievement. One way of motivating students is for today’s teacher to get to know students more personally in order to find out what motivates them. Lee Morganett (1991) suggests that teachers, “ask students about their weekends, goals and aspirations, and opinions, and that what you talk about is probably less important than the ‘l {I l A" ’ 1' fi‘r'fib' fact that you were interested enough to ask and listen”. w.‘ Morganett gives other suggestions to help students’ self- esteem and motivation such as creating a supportive classroom environment and creating an environment where questions and answers are encouraged and valued. Morganett (1995) also believes that good teacher—student relationships develop effective classrooms because students want teachers to be interested in them. It gives them a feeling of importance by being accepted and valued by others. They are also more likely to do what the teacher asks them to. According to the article, “What Helps Students Learn?”, the different kinds of classroom instruction and climate had nearly as much impact on learning as the student aptitude categories that were studied (Wang 1994). Wang, Haertel, and Walberg also reinforce the idea that effective classroom management increases student engagement, decreases disruptive behavior, and makes good use of class time. Not only does a well-maintained classroom promote success, but it also can have an effect on the climate of the entire school. James Sweeney (1992) states, “some factors for improving school climate include a supportive, stimulating environment, student-centered and positive expectations”. Ideally, cooperative learning creates long term social effects in addition to the mastery of subject knowledge. It develops strength in interaction and communication skills in students. It creates a social interdependence, which according to Johnson and Johnson (1992), “leads to promotive zinteraction as individuals encourage and facilitate each NSother’s efforts to learn”. This type of positive reinforcement and encouragement leads to students becoming (___*w,,aa mo£g_agtiye_learners. Johnson and Johnson (1992) refer to this as cognitive restructuring which they define as, “what is needed in order for information to be retained in memory and incorporated into existing cognitive structures, the learner must cognitively rehearse and restructure the material”. Cooperative learning raises students’ self- esteem in the classroom, which ultimately improves the climate of the entire school. Statement of Problem and Rationale Chemistry is a difficult body of knowledge containing many abstract concepts. Most high school students take it because it is suggested as part of the curriculum for those planning on attending college. The students have no idea what the class is about, what skills are necessary, and the amount of work required. I remember my high school chemistry class. The teacher taught using the "traditional" method, first lecturing on the subject then assigning individual practice. For some topics this method is successful, but not for all topics. When the topics were more difficult some students would seek additional help from the teacher. Others would ask other students for help. However, some students were not comfortable asking the teacher or others for help. These students were often unsuccessful and quite frequently resented the teacher and/or the class. When I began teaching I wanted everyone to be successful, just like every new teacher. I wanted to make chemistry fun and interesting. (It wouldn't be a bad thing if a few students even ended up liking chemistry as much as I do.) I soon found out that this goal was a lot more difficult than I had expected. There were some topics that readily engaged the students and then there were those where it just was not interesting to them. To top it off, I still found a few students that weren't asking me or other students questions when they needed help. I would try to 10 make an extra effort to approach these students whenever possible, but more times than not, they said they didn't need any help. This is when I decided I needed to try something different in my classroom, cooperative learning. The work described in my thesis documents the effectiveness of cooperative learning in helping students acquire knowledge in high school chemistry. To accomplish this, I restructured student assignments and my methods of presenting new information to develop cooperative problem- solving behaviors. Those behaviors are: 1) State your own ideas. 2) Listen to others; give everyone a chance to talk. 3) Ask others for their ideas. 4) Give reasons for your ideas and discuss many different ideas. The focus for this study was the information in the first semester of the class culminating with stoichiometry, at which point the cooperative problem-solving behaviors should be well established. I compared the test scores for the five units of the 1994-95 chemistry class, the individual working group, which had no structured cooperative instruction, to those of the 1995-96 chemistry class, the cooperative learning group. I hypothesized that the class taught with the cooperative learning approach would perform better. My rationale for this study was based on my observations of my past chemistry classes. My most successful students were self-motivated. Their assignments were completed on time, achieving approximately 75% or 11 (U CT I‘D better on the assignment. They were not afraid to ask for help, whereas my least successful students would come to class unprepared, having not attempted their homework, and having a poor attitude toward the class. I made the assumption that these behaviors must be due to poor motivation. Chemistry is a sophomore elective which requires Algebra I with a C or better and approval from their current science teacher (which is usually Biology). This results in a group that is usually highly motivated. Why do some of these students not even attempt to do their homework? One possible reason could be that these students really don't understand the material and are afraid to ask for help. Another reason could be that these students are afraid they will get the wrong answers, they are afraid of failing, so they don't try. Some students may simply believe that they don't have the ability to do the assignment. During my years of teaching, I have seen students that fit into each of these categories. I believe that the best way to overcome these factors is to create a supportive classroom environment, one in which a student can present a wrong answer without ridicule and not have to compete with one another. It is important that their peers and teacher not only show that they are interested in them but that they care about them. This atmosphere can be established through cooperative learning. In the past, I taught stoichiometry by demonstrating problems on the board, followed by guided practice where the 12 (N .s C students would work the problem out in their notes and then I would work the problem out with them on the board. After the students felt they had tried enough practice problems they would work on worksheets individually. Following this, the worksheets would be corrected in class, questions would be answered, problems would be worked out if necessary, and then students would be quizzed. This procedure was followed for each type of stoichiometry problem required of the student. Then, before the final evaluation, the students would complete a laboratory experiment. This included prelab questions, the experiment, the analysis, calculations, and synthesis questions. The prelab questions were discussed before the experiment began and students were given guidance throughout the experiment and final questions and calculations. This method worked well for those students that were self—motivated and high achievers. But as all educators know, not all students learn by the same means. I also felt that the only thing the students learned from the experiment was proper laboratory techniques. Yale High School has just over 600 students. The ethnic make up is predominately white with 1-2% minority students. Yale School District is the largest bussing area in St. Clair County with as many as 70% of the students riding busses. Roughly 10-15% of graduating students go on to college, many of them to the two year community college. The socio-economic standing of the community is mostly farm land and many trade workers. 13 Implementation of Unit The primary source for the content area of my thesis came from Heath: Chemistry, D.C. Heath and Company 1993. My resources used for redesigning the way I present the subject were Designing Groupwork: Strategies for the Heterogeneous Classroom, Elizabeth_G. Cohen 1989, Cooperative LearningfiResources for Teachers, Spencer Kagan, Ph.D. 1989 Edition, and The Cooperative Classroom: Social and Academic Activities, Jaqueline Rhoades and Margaret E. McCabe, 1992. In order to implement cooperative learning in my classroom, I had to change all my units. I had to begin on the first day of school, teaching chemistry in new ways, and also teaching the students how to work with others. Chapter One, Activities in Science, was a great place to start teaching cooperative methods because a lot of the information that was taught to the students in previous science courses and therefore the information just needed to be reinforced. On the first day of school teachers are always busy with the formalities. I took advantage of this by using an introduction game. I needed to learn the students’ names quickly so I had the students introduce themselves. They had to think of an adjective to describe themselves that began with the same letter as their first name. Then they had to explain why they chose that adjective. Being tenth l4 graders, most of the students already knew each other so they felt fairly comfortable with one another. However, a few students were a little nervous having to stand up and introduce themselves. Overall, it went very well. On the second day I put students into their base groups. These were their permanent groups of 3-4 students for the first chapter. I found four students per group to be the best for most activities. The students were chosen randomly for this base group since I had very little prior knowledge of the students. Once in their groups, they were told how to be a good listener. This was to be a strong basis for the rest of our activities throughout the year. The steps for being a good listener were then posted in the room. Next we did an activity to develop listening skills and skills on how to give directions in a way that others can follow (See Appendix A). When we began, so many students were saying that this was going to be easy; but many students became frustrated instead because they could not get their receiver to duplicate their design. Even though they were frustrated, they did learn from their mistakes and those in their groups did better after seeing the difficulties that the first pair had. Next is an outline of the units in the first semester with the activities and the cooperative learning techniques used in each. For a more complete description of the lesson plans, see Appendix C. Each unit is from the course 15 textbook mentioned above. Units were taught by objectives with activities listed for each. I still showed each step of the problems, making sure to write the steps out in words. Then we went through the practice problems together, following all the steps. Next, instead of individual practice, the students worked in pairs on a "Pairs-Check" worksheet (See Appendix B). One student worked on a problem while their partner watched, making sure they followed the correct procedure. The students then switched roles. When both were finished with their worksheet, they got together in a group of four and compare their work and answers. After this, the students were given an assignment that they did themselves. However, they were allowed to compare their work with that of other group members when they completed the assignment. Another technique used was Sharearound. In this activity, the person to the left of the teacher gave the first piece of information that they had in their outline. Then they answered any questions. The process continued around the circle with the teacher adding any information deemed necessary. The technique Numbered Heads Together was also used. In this activity, each student in the group was assigned a number 1-4. The teacher drew a number, and that person was responsible for reporting their group’s answer and explains how they got that answer. The other members of the group were responsible for staying on task, recording the information, and watching the time. This process was followed for each type of problem that was 16 introduced. More time was also spent on the experiments in my cooperative learning class when compared to my traditional class. The experiment went from lasting one and a half days to two and a half days. More time was spent on discussing the conclusion and the results. In order to implement cooperative learning, many changes had to be made in the curriculum. First of all, cooperative learning had to be started on the first day of instruction and carried out throughout the completion of my study. Second, cooperative learning techniques take much more time than traditional methods. Third, due to the time, cuts in the information taught had to be made. I chose to eliminate the teaching of determination of empirical and molecular formulas for compounds and the determination of the limiting reactant in a chemical reaction to predict the amount of product that can be formed. Table 1 Activities of Science 3.5 weeks Scientific Topic Activities Cooperative Learning Technlquee OUedWawkELC lflwflhg Eflmmmmmm! Asagnmnfiununi NmnhaadHabeogwMH \Nmpflp Enxmnmmtt1 Campmflgcwunngmmps OHaflMaHlELF’ IMSMNmmflflmflkut HNmJHedUWbmymem OdeNesGrHJ Lmammamgmmn Gmmpwum OMafimunLKJ. deqmsmmc Symmammmi Learning Guide Numbered Heads Together 17 Table 2 DescribingiMatter Scientific Topic Activities Objectives A.B,C,D Stump the teacher Objectives E,F,G Objectives H,I,J Table 3 Assignments 1-2 8. 1-3 Lab Investigation Assignment 1-4 Stump the teacher Elemental Bingo Assignment 2-2 Assignment 2-3 Assignment 3—1 Assignment 3—2 Assignment 3-3 Experiment 2-1 Synthesis Lab Questions Learning Guide Chemical Reactions & quuationfis Scientific Topic Activities Objectives A.B,C,D,E Chapter 3 part 1 Objectives F,G,H,l Assignment 1-1 Assignment 1-2 Experiment 3-1 pre lab Analysis 8. Conclusion Assignment 1-3 Balancing Equations Assignment 1-4 Assignment 1-5 Chapter 3 part 2 Assignment 2-1 Assignment 2-3 Assignment 2-5 Lab Investigation Learning Guide 18 3 weeks Cooperative Learning Techniques Sharearound Base Groups Base Groups Sharearound Base Groups Numbered Heads Together Sharearound Base Groups Pairs-Check Worksheets Base Groups Numbered Heads Together Base Groups Base Groups Pairs—Check Worksheets Numbered Heads Together Base Groups Numbered Heads Together Sharearound 3.5 weeks Cooperative Learning Techniques Sharearound Numbered Heads Together Numbered Heads Together Base Groups Numbered Heads Together Numbered Heads Together Sharearound Pairs-Check Worksheets Base Groups Numbered Heads Together Sharearound Numbered Heads Together Numbered Heads Together Numbered Heads Together Base Groups Numbered Heads Together Table 4 Molar Relationships Scientific Topic Activities Objectives A,B,C Chapter 4 part 1 Molar Conversions Experiment 4-1 Molarity Significant Digits Table 5 Stoichiometry Scientific Topic Activities Objectives A,B,C Mole-Mole Homework Molarity 8. Replacement Homework Experiment 5-1 Objectives D,E Percent Yield Lab Investigation 19 3 weeks Cooperative Learning Techniques Sharearound Pairs—Check Worksheets Numbered Heads Together Base Groups Pairs-Check Worksheets Numbered Heads Together Sharearound 3 weeks Cooperative Learning Techniques Pairs-Check Worksheets Numbered Heads Together Pairs-Check Worksheets Wrap-up Numbered Heads Together Base Groups Numbered Heads Together Base Groups Evaluation No pre- or post-test was given for either the individual working group or the cooperative learning group. Both groups came into the chemistry class with either little or no chemistry background. The pre-requisites for both groups were the same. Students were to be at least a sophomore and have completed both Algebra I and Biology with a C average or better. All student records were checked to make sure they met the pre-requisites. At the time of the study there was also an Honors Chemistry class offered. This class usually consisted of students that had completed Honors Biology and Geometry as freshmen. Some had Algebra I; however, they had to be recommended by their Honors Biology teacher. These students are usually ranked as the top 10-15% of their class. Therefore, they were not a part of my study due to the advanced nature of the class and the use of a different textbook. This was important so that the study was done on a more level field of study. The quantitative evaluation focused on grades based on homework, quizzes, laboratory activities, unit tests, and the semester exam. These letter grades represented for an A 90 - 99%, B 80 — 89%, C 70 - 79%, D 60 - 69%, and an E was below 60 %. For a visual representation of test results, see Appendix F. 20 In Unit 1, Activities of Science, the individual working method showed a typical bell curve for the test results, where the majority of the students, 44%, received a C. The curve for the cooperative learning group shifted to the left. There was a decrease in the number of C’s by 21%, 0’5 by 12%, and E’s by 7% followed by an increase in the number of A's by 11% and B’s by 29%. The majority of the students, 52%, received 8’5. 89% of the students in the cooperative learning group received a C or better versus the individual working group method where only 70% of the students received a C or better. Figure 1 Scores for Activities of Science 60%r - e _ ..~ lllllllllllllllllllllllllllllllll For Unit 2, Describing Matter, the improvement in grades was less dramatic. The percentages of B’s increased by 7%. Unfortunately the percentages of E’s also increased by 1%. The number of D's decreased by 9%, while the percentages of A’s and C’s remained unchanged. Overall, in the cooperative learning group, 65% of the students received a 70% or better, compared to 58% in the individual working group. Figure 2 Scores for Describing Matter 30%" l 25% l 20% In Unit 3, the cooperative learning group’s percentage of E’s stayed the same at 2%, B’s fell 3%, and D’s fell by 13% with no D’s for any student. The C’s increased by 4%, and A’s increased by 12%. Ninety-eight percent of the 22 students received a 70% or better compared to 85% in the individual working group. Figure 3 Scores for Chemical Reactions 4W%< 2U%< 1U%< W%+ D In Unit 4, there was a decrease for the cooperative learning group in A’s by 3%, D’s by 2%, and E’s by 9%, with an increase in B’s and C’s by 7% each over the individual working group. Sixty-three percent of the cooperative learning students received a C or better compared to 52% of the individual working group. 23 Figure 4 Scores for Molar Relationships I wanted to end my study with Unit 5, Stoichiometry, mainly because its one of the harder concepts and it brings everything from chapters 1-4 together. However, I was only able to teach the information for chapter 5 for the individual working group and not test them. The students never took a chapter test; instead the information on stoichiometry was tested on their midterm exam. I was able to collect data for the cooperative learning group. 88% of the students received a C or better, which I feel is successful even without a comparison to the individual working group. 24 Scores for Stoichiometry 20%‘ 10% lb 0% I also gave two surveys to the students in the cooperative learning group in order to gain some knowledge about them as learners and their attitudes toward science. Students were asked to complete the first survey, titled Science Survey (Appendices G & H), at the very beginning of the first semester and again at the end of the first semester. It focused on the students’ interest in science and why they do the work in a science class. I have found that students who succeed in science end up feeling good about science, which reflects in their self-esteem. The students were asked to rate how they felt on a scale from 1 25 to 5 about various statements, where 1 meant they strongly disagreed and 5 meant they strongly agreed. Table 6 SCIENCE SURVEY: QUESTION SET I STRONGLY AGREE STRONGLY DISAGREE QUESTION 1 5 4 3 2 1 BEFORE 6% 47% 30% 13% 4% AFTER 19% 43% 25% 11% 2% QUESTION 2 5 4 3 2 1 BEFORE 9% 34% 25% 17% 15% AFTER 42% 30% 17% 8% 4% QUESTION 3 5 4 3 2 1 BEFORE 1 1% 42% 30% 1 1% 6% AFTER 9% 45% 34% 1 1% 0% QUESHON4 5 4 3 2 1 BEFORE 13% 36% 34% 15% 2% AFTER 17% 38% 26% 19% 0% QUESHONS 5 4 3 2 1 BEFORE 8% 28% 43% 15% 6% AFTER 4% 40% 30% 17% 9% QUESTION 6 5 4 3 2 1 BEFORE 0% 15% 47% 21% 17% AFTER 0% 17% 45% 25% 11% QUESTION 7 5 4 3 2 1 BEFORE 8% 34% 49% 6% 4% AFTER 4% 40% 32% 17% 9% QUESTION 8 5 4 3 2 1 BEFORE 9% 8% 26% 19% 38% AFTER 13% 9% 17% 21% 38% 26 Question I asked the students if they liked science. Before learning about and using cooperative learning only 6% strongly agreed, whereas after 19% strongly agreed. Question 4 asked if students thought science was fun and interesting. Before, 13% strongly agreed, after, 17% strongly agreed. For both of these questions the percentages increased toward more positive results as did the majority of the other questions. This shows that cooperative learning increased students’ personal feelings toward science in addition to raising quantitative scores. A second survey (Appendix I) was also given to both groups before and after the first semester. It was called “A Self-Test: Characteristics of Achievers”. Thirteen questions were asked and the students were to respond with: I’m always like this, I’m usually like this, I’m sometimes like this, I’m seldom like this, or I’m never like this. When comparing the before results with those after, most responses changed to a more positive response. For example, question 11, “Like to achieve and dislike not achieving” went from a 53% to a 64% for the “I’m always like this” response, with no seldoms or nevers. This shows that the students have more of a desire to achieve. Question 12, “Want to do a better job in better ways” went from a 49% to a 57% in the always category, with no seldoms or nevers. However, question 1, “Self-reliant and self—confident”, did 27 not give the result I expected, although it did improve overall. Before, 17% said always, 55% said usually, 21% said sometimes, 6% said seldom, and 2% said never. After, 13% said always, 58% usually, 26% said sometimes, 2% said seldom, and 0% said never. I hoped to see a higher percentage for always. I really felt that the students were more confident in their work since using cooperative learning. Table 7 ASbflTaw:CNwamammxrwAdmwem QUESTION 1 ALWAYS USUALLY SOMETIMES SELDOM NEVER BEFORE 17% 55% 21% 6% 2% AFTER 13% 58% 26% 2% QUESTION 2 ALWAYS USUALLY SOMETIMES SELDOM NEVER BEFORE 26% 60% 9% 2% 2% AFTER 30% 58% 1 1% QUESTION 3 ALWAYS USUALLY SOMETIMES SELDOM NEVER BEFORE 45% 36% 13% 6% 2% AFTER 45% 49% 6%: QUESTION 4 ALWAYS USUALLY SOMETIMES SELDOM NEVER BEFORE 24% 41% 24% 4% 4% AFTER 30% 45% 21 % 4% QUESTION 5 ALWAYS USUALLY SOMETIMES SELDOM NEVER BEFORE 13% 55% 23% 6% 4% AFTER 22% 39% 32%» 9% QUESTION 6 ALWAYS USUALLY SOMETIMES SELDOM NEVER BEFORE 19% 38% 36% 2% 4% AFTER 21 % 47% 32% 2% 28 QUESTION 7 ALWAYS BEFORE 4% AFTER 13% QUESTION 8 ALWAYS BEFORE 28% AFTER 32% QUESTION 9 ALWAYS BEFORE 43% AFTER 30% QUESTION 10 ALWAYS BEFORE 1 1% AFTER 15% QUESTION 11 ALWAYS BEFORE 53% AFTER 64% QUESTION 12 ALWAYS BEFORE 49% AFTER 57% QUESTION 13 ALWAYS BEFORE 26% AFTER 38% USUALLY SOMETIMES SELDOM 43% 30% 17% 30% 32% 6% USUALLY SOMETIMES SELDOM 52% 17% 4% 45% 17% 6% USUALLY SOMETIMES SELDOM 40% 1 1% 4% 55% 1 1% 2% USUALLY SOMETIMES SELDOM 49% 30% 9% 49% 24% 7% USUALLY SOMETIMES SELDOM 40% 9% 34% 2% USUALLY SOMETIMES SELDOM 40% 22% 2% 40% 3% USUALLY SOMETIMES SELDOM 42% 23% 7% 34% 26% 2% NEVER 6% NEVER NEVER 2% NEVER 2% 2% NEVER NEVER NEVER 2% At the end of first semester I had the students in the cooperative learning group fill out a questionnaire (Appendix #). working in groups was beneficial?” responded with yes, The second question was, continue to work in groups second semester? The first question asked “Do you feel that 93% of the students 3.5% no and 3.5% said sometimes. 29 Explain.” “Do you think we should 93% said yes, 3% said no, 4% didn’t know. Some of the reasons they gave for continuing group work were: > > V7 ‘V ‘7 'V > “you get help from other people” “share ideas” “explain how in a different way” “comparison to see if you’ve done it right” “improved my grade” “makes learning interesting and fun, opportunity to teach others" “students explain it easier” There were only two negative responses to the question. Their reasons for not continuing were: > > “sometimes your group confuses you” “better on your own” The third question was, “Were group assignments, such as Pairs-Check, useful? Explain.” 98% said yes, 2% said no. Some reasons for saying yes were: > “you could find out what you were doing wrong and the group would help you correct it” “getting help from the rest of the group helps understand the assignment” “can all help each other” “you got to see if you did it right, and if not they could explain it to you” 30 > “it gave somebody else a chance to give you suggestions on what your (sic) doing wrong” Those that responded no gave no explanations. The fourth question was, “If we were to continue work in groups, how would you suggest that the groups be chosen? Explain.” 36% wanted the teacher to pick groups using the same method as before, 22% wanted random groups, 20% wanted to pick their own groups, 11% doesn’t matter, and 9% wanted to keep the same groups as first semester and 2% other. 31 Discussion and Conclusion The key part to the unit Activities of Science was learning the SI units for measurement and being able to convert from one unit into another. The method I taught was the factor-label method, which is also used in many chapters of the text following this one, especially in Molar Relationships and Stoichiometry. Based on the student performance results of Activities of Science, I feel the students in the cooperative learning group were very successful. I think the cooperative learning tool that helped the most was the Pairs-Check worksheets that were developed for this topic because the students were able to use the tool effectively to communicate with other students in their group. The unit Describing Matter really starts the study of chemistry. Every topic was new and most students have a difficult time. Usually, if a student is not going to make it through the course, this is where they begin to fail, setting them back too far to ever keep or catch up. The results in Figure 2 of the cooperative learning group were very disappointing for me. I was hoping to see more improvement compared to the individual working group than I did. Students were to learn the difference between pure substances and mixtures, which they can do. They were also asked to learn the symbols and names of molecular and ionic 32 compounds, which is where the students have difficulties as measured by the number of questions they asked and uncertainty when asked to respond to a question. I found that they do poorly when they do not know the symbols and names of the elements. The students in both groups were quizzed on the element’s names and symbols starting the first week of school. Most students really liked the little quizzes and considered them “easy points”. Unfortunately there were still many students who did not take the time to learn them. I feel in order to correct this I need to better motivate the students. Group work, in this case, does not work well because it becomes the individual’s responsibility to know them before the group can help with the process of writing formulas and naming compounds. I was very pleased with the results of Chemical Reactions and Equations, especially after the disappointing results of the previous unit, because the students do need to know the content of the matter unit in order to proceed to Chemical Reactions and Equations. This unit focused on writing balanced equations, word equations, identifying the types of reactions, and predicting products in chemical reactions. Working on Pairs-Check worksheets and doing assignments in groups really was beneficial to both the students and myself, especially with balancing equations, when a student can develop different procedures to end up 33 with the same answer. I noticed that students in several groups were showing each other how to balance equations using different procedures, not just the method demonstrated. This took away a lot of the frustration from the students that were having difficulties as well as from me when a student just could not do it the way I demonstrated. With Molar Relationships, there was a small positive difference in scores. I can not say that this difference was due to cooperative learning. Molar Relationships was one of the chapters where I decided to omit two sections that I had taught to the individual working group. The omitted sections were determining empirical and molecular formulas, which are not considered core material. It can also be a challenging topic for the students that are struggling in the course. Therefore, the increase could be due to the elimination of these topics. As far as Stoichiometry was concerned, I have no data to compare, but the cooperative learning group was very successful as evidenced by my interactions with these students. Students, for the first time in my teaching history, were commenting on how easy stoichiometry was to them. I was shocked but delighted to hear this. I feel success was due primarily to an early mastery of the factor- label method taught earlier, which in part, was a result of 34 cooperative learning. Again, the other factor that had a positive impact was the Pairs-Check worksheets. These allowed students to see the cooperative learning process of working together and communication clearly and identify any mistakes that they may be making along the way. Together with the support of their partner and their group they could make the proper corrections and learn from their mistakes. I am pleased that the overall grades improved from year one to year two, but I am more pleased with some of the responses to the questionnaires. More students in the second year than the first year said that they liked science after cooperative learning and nothing makes a science teacher feel better than hearing students say that. Students in the cooperative learning group also were striving to achieve, if not for themselves, then for their group. I even heard a few students say “I like this class so much better than Biology” and they actually had better grades in Biology than in Chemistry. I strongly believe that this has to do with the method of learning, not the class itself. Finally, based on the final survey that asked students if we should continue with group work, I would say the students preferred this method of learning. These students came to my class because it was a college prep course. They were not especially fond of science and had no experience working in groups. I have 35 watched these students become more excited about science and have definitely seen an improvement in their ability to work with others. As a teacher, I have learned from watching the students work with one another. I have learned new methods of presenting information to the students. I learned to be more flexible in the classroom and less hesitant to change the lesson at any given moment to adapt to the students’ needs. Basically, I feel more confident about the job I am doing and will definitely continue to use cooperative learning in my classroom. Actually measuring self-esteem is very difficult to do and not knowing the students very well before makes it even more difficult to tell if the students’ self-esteem has increased. I do know that the students work very well with others once they have had the class and they no longer hesitate to ask or answer questions in class, in their groups or even outside of the class. Whether it is the cooperative learning activities or my new approach to teaching (making me a better teacher), that is the reason for these improvements is really unclear, but the fact that it seems to be effective is enough for me. Since this study, I have continued to use the Pairs—Check worksheets and have students work in groups as well as maintain my role as facilitator. Some activities, such as the Sharearound, have been used less frequently due to a 36 change in the structure of our school day. I have also added a motivational tool that I use for the groups to get them to help one another more. The groups receive bonus points based on improved quiz scores and the groups with the most bonus points receive extra credit. It has been a great motivator as well as a comfortable addition to cooperative learning. 37 Appendices 38 Appendix A Listening Activity Each group receives two identical bags containing the same number and the same shaped objects. One person in the group is designated as the giver of directions, another as the receiver of the directions, and the remaining group members will be judges until the roles are rotated. The giver and receiver are to turn their desks so that they are back to back. The giver then takes the different shaped objects and makes one design. Once the giver’s design is set they are to give directions to the receiver on how to build the same design. They may use any oral method to describe this design. The students are encouraged to use common vocabulary, such as common names of the shapes to help the receiver choose the right objects. The judges are to make sure that the giver or the receiver does not look at one another’s designs until they are ready to compare them. Once this is done the students will rotate so that eventually everyone has been a receiver and a giver at least once . 39 Name: Topic: Metric Conversions Date: 1. 4.9 cm = 2. 6.47 kg 3. 2.15 mL 4. 81 mm = 5. 5281 mm2 Appendix B Pairs-Check Worksheets CITI Name: Topic: Metric Conversions Date: 1. 3.24 cL = mL 2. 9.7 km = m 3. 471.2 g = kg 4 3 6 mm = dm 5. 2.7 km2== m2 40 Pairs-Check Name: Name: Topic: Density Topic: Density Date: Date: 1. What is the density of 1. Given a mass of 13.5 g 19.3 g of a substance that and a density of .902 g/cmé, has a volume of 1.45cm&? calculate the volume. 2. A substance has a 2. What is the density of density of 2.2 g/cm3anmi 8.34 g of a substance with a a volume of 1.45 cm3. volume of 16.3 cml? What is it’s mass? 3. What is the volume 3. What is the mass of a of a substance with a mass substance with a density of of 19.3 g and a density of 7.86 g/cm? and a volume of 2.7 g/cm‘? .902 cmL? 41 Pairs-Check Name: Name: Topic: Naming and Writing Topic: Naming and Writing Formulas for Binary Compounds Formulas for Binary Compounds Date: Date: 1. SiC14 l. ASFs 2. N02 2. NBr3 3. N204 3 NO 4 . HO 4 . C4N2 5, tetraarsenic decaoxide 5. sulfur hexachloride 6. phosphorus trichloride 6. tetraselinium dinitride 7. carbon disulfide 7. silicon monocarbon 8. dichlorine monoxide 8. diphosphorus tetroxide 42 Pairs-Check Name: Name: Topic: Ionic Compounds Topic: Ionic Compounds Date: Date: 1. calcium chloride 1. Lithium sulfide 2. sodium oxide 2. strontium fluoride 3. copper (I) sulfate 3. Iron (III) phosphate 4. aluminum chromate 4. Magnesium hydroxide 5 . CIBrz 5 . CUNO3 6. SnCl. 6. SnSO. 7 . NH4OH 7 . H28 8 . K3PO4 8 . Caapz 43 Pairs-Check Name: Name: Topic: Balancing Equations Topic: Balancing Equations Date: Date: 1. _K + _F2 -) _KF 2. _Ca '1' H20 9 _Ca( H)2 1' _Hz 3. _NaCl03 -) _NaCl + _02 4. _ZnO + _HCl -) _ZnClz + _ H20 5. _CuSO. + _Fe -) _Fe2(SO..)3 + _Cu 1. _c12 + _KI -) _KCl + _I2 2. _Mg + _02 -) _MgO 3. _NH4Cl + _Ca(OH)2 -) _ _NH3 + _HZO + _CaC12 4. _CU2S + _02 -> _CuzO + _SOz 5. _A1203 -) _Al + _02 Pairs-Check Name: Name: Topic: Molar Conversions Topic: Molar Conversions Date: Date: 1. 64.3 g of PbBrz 1. 3.33 x 1025 molecules to molecules of I2 to grams 2. 0.846 mole of HF to 2. 3.98 moles of C02 to molecules molecules 3. 8.50 g of Hg(NOfi2 to 3. 0.35 mole of benzene, moles Cdk, to grams 4. 4.85 x lofi’formula units 4. 30.8 g of MnCfih to of Cues to grams formula units 45 Pairs-Check Name: Topic: Molarity Date: 1. Find the molarity given 5.23 g of Fe(NOfi2 in 100.0 cm? of solution. 2. Find the molarity given 9.94 g of COSOqlJl 250 mL of solution. 3. How many grams of NiClz are contained in 1.00 L of a 3.00 M solution? 4. How many grams of AgF are contained in .500 dm3 of a 1.50 M solution? Name: Topic: Molarity Date: 1. Find the molarity given 8.55 g of NHAI in 50.0 cm? of solution. 2. Find the molarity given 44.3 g of Pb(ClOnz in 250 mL of solution. 3. How many grams of CoClz are contained in 250 mL of a 4.00 M solution? 4. How many grams of Cd(IOfi2 are contained in 250 cm3 of a .00200 m solution? 46 Pairs-Check Name: Topic: Mole-Mole Date: 1. Magnesium burns in oxygen to produce magnesium oxide. How many moles of oxygen are needed to burn 0.52 mol of Mg? 2. How many moles of HNO3 will be produced when 0.51 mol of ka reacts according to the following equation: N205 + HzO -) 2HNO3? 3. How many moles of HCl are needed to react with 5.70 mol of Zn? 2HCl + Zn ‘9 ZnClz + H2 Name: Topic: Mole-Mole Date: 1. How many moles of Al(NOfi3 will be produced when 0.75 mol of AgN03 reacts according to the following equation? 3AgNO3 + Al -) Al(NOg)3 + 3Ag 2. Lead will react with hydrochloric acid to produce lead (II) chloride and hydrogen gas. How many moles of HCl are needed to react With 0.36 mol of Pb? 3. How many moles of HCl are needed to react with 2.3 mol of Zn? 2HCl + Zn -) ch12 + H2 47 Pairs-Check Name: Topic: Molarity and Replacement Reactions Date: 1. How many grams of chromium would be needed to replace the copper in 200 mL of a 0.75 M solution of copper (II) sulfate? 2. How much tin will react with 32.0 mL of a 1.75 M solution of hydrochloric acid? Sn + 2HCl 9 H2 + SnClz 3. What volume of 0.5 M ZnBr2 reacts with 75 mL of a 0.75 M solution of Ca(OH)2? ZnBr2 + Ca(OH)2'9 Zn(OH)2 + CaBrz Name: Topic: Molarity and Replacement Reactions Date: 1. How many grams of chromium would be needed to replace the copper in 150 mL of a 0.50 M solution Of copper (II) sulfate? 2. How much tin will react with 47.2 mL of a 2.55 M solution of hydrochloric acid? Sn + 2HCl 9 H2 + SnClz 3. What volume of 0.75 M ZnBr2 reacts with 87 mL of a 0.55 M solution of Ca(OH)2? ZnBr2 + Ca(OH)2'9 Zn(OH)2 + CaBrz 48 Appendix C Daily Lesson Plans Appendix C—l Chapter 1: Activities of Science Part 1: Applying a Scientific Method Objective A: Recognize how knowledge obtained from the study of chemistry can be applied in your life. Objective B: Explain why communication is an important aspect of obtaining scientific knowledge. -Observation vs. inference Objective C: Describe the functions of a hypothesis and a theory in the scientific method. Day 1: Discussion of the assigned reading. All students will get in a circle and use a method known as Sharearound. The person to the left of the teacher will give the first piece of information that they have in their outline. At this time questions or comments can be given. Then the process keeps moving around the circle. The teacher may add any information as the exercise goes along and students may add to their outlines at anytime. The first time I did this I felt that it had failed. The students did not seem to take an active part in the 49 discussion and they had to be reminded of how to be a good listener. But one time does not give the activity a fair chance and I had to remind myself that it was new for the students. Day 2: The first group assignment, page 8, and questions 1- 5. The activity used for this was called Numbered Heads Together. Each student in the group is assigned a number 1, 2, 3, or 4. A number is drawn and that person will be responsible for reporting their group’s answer and explain how they got their answer. The other members in the group will also have jobs. One will be the recorder; they are responsible for writing the answers on a piece of paper and making sure all group members names appear on the paper. Another will be responsible for keeping everyone on task so that the group is productive. And the final group member is responsible for keeping track of the time in case we have a time limit. All members are expected to participate. This activity went very well. For their first group assignment I really expected students to get off task easily, but they didn’t. Some of the reporters were a little nervous but managed to come through for their group. At the end of the period the students had one final individual assignment. It is called Wrap—up. The student is to answer one question, which varies depending on the assignment. They had to complete the following statement: 50 One new thing that I learned was ...(being specific). Day 3: Group assignment using NUmbered Heads Together. First answer questions for objective A on page 33, 1-4 of the text. Then report. Second, objective B on page 33, 5-8. Then report. Last, objective C on page 33, 9-11. Then report. Each time they are to report a new number is selected to give others an opportunity to report. Doing the assignment in this method does take a lot more time, but I felt that the students were learning. And by having every group report their answer and explaining how they got it, it reinforces the information. Day 4: Quiz on Objectives A, B, and C. All my quiz questions are broken into objectives to match the format of the book and homework assignments. The questions also reflect those found in the homework, therefore, there are no surprises for the students. Next, the students answered prelaboratory questions for the up coming experiment. Day 5-6: Experiment 1.1, Working in the Chemistry Laboratory. In this lab, students learn about and use apparatus in the chemistry laboratory. The major goal of this lab is for students to become familiar with laboratory equipment and procedures while learning and applying safety precautions when working in the lab. Students also perform an 51 experiment that shows how carbon dioxide causes limewater to become cloudy, while the gas from the reaction of magnesium and hydrochloric acid (hydrogen gas) does not. I had never done this lab before because of the time it took and the lack of equipment. The students worked in their base groups, dividing the parts of the lab up equally so all were participating. In the future, I would like to break the students up into pairs so that each student can experience every part of the experiment. Day 7: Finish any part of the lab that may not be complete. Next, complete the analysis, conclusion, and synthesis questions. For any lab, whether the students work in their. base groups or pairs, they will always get back in their base groups to compare data and answer the questions together. Day 8: The groups took turns reporting answers and I explained answers in more detail where needed. Wrap-up: Why do you think this lab was important? Homework: Read and make an outline for chapter one, part two, pages 9-15. Part 2: Using Mathematical Knowledge Objective D: Differentiate between quantities and numbers. Objective E: Recognize the meaning of SI units, 52 including their abbreviations and the quantities those units describe. Objective F: Apply problem-solving strategies to convert SI units and to calculate derived quantities from base SI units. Day 9: Lecture: Use factor-label method for conversions. Teach the students a saying to help them remember the order of the prefixes: Kangaroos Have Dreams of Delicious Chocolate Milk. Kilo, hecto, deka, base, deci, centi, milli. Homework: page 15 8-14. I chose lecture for this section due to the math that was involved. The meaning of the prefixes and the method of conversions were discussed, followed by many examples. Day 10: In base groups, compare results. If there are any disagreements in any answers take the time to look at each other’s steps and check the work. Next, the groups may ask the teacher questions. This assignment was for practice but will be collected so I can look it over. Pairs-Check Worksheet: The base group will break up into two pairs. One person in the pair is to do the first problem, while the second person acts as a coach. If the coach agrees that the person has done the first problem correctly, they are to give him/her praise and then switch roles. When both have finished the first problem, they need to check 53 their answers with the other pair in their group. If both pairs don’t agree they need to figure out what they did wrong. They may ask the teacher for help if they are unsure. When both pairs agree, they give a handshake and proceed to the next two problems and follow the same steps. (See Appendix B for an example of the Pairs—Check worksheet.) In base groups: Objectives D, E, F, page 33-34, 12—28. They are to have individual papers, but are encouraged to work together. Any questions or problems that are not finished in class are to be completed as homework. Students may contact group members if help is needed. The students liked the worksheet, but felt the handshake was a little corny. So we replaced it with any kind of positive saying or motion. Some groups just said good job; others liked to do a high-five. Most groups finished objectives D and E before they left, and were beginning objective F. Day 11: Individuals are chosen randomly to go to the board and write the answer to a designated problem. They will be responsible for explaining how they got their answer. I had many students come in before class asking for help on some of the problems in objective F. Due to this the class was given time to finish their assignment in their groups before answers were written on the board. Day 12: Quiz on objectives D-F. 54 Instruct students how to make a data table and a graph. Homework: page 23, 17, 18, 23, and 24. This assignment will help assess prior knowledge. Part 3: Developing Tools for Analysis Objective G: Construct tables and graphs to organize data. Objective H: Determine density by interpreting data on a graph. Objective I: Calculate density by using problem-solving strategies. Day 13: In base groups: Objective G, page 34-35, 29-31. Each group will be given a specific part of number 29 to do. Then using this data they will answer questions 30 and 31. Homework: Objective H, page 35, 32—33. Students may begin work with their base group but will not have time to finish it in class, therefore, they will have to finish it at home individually. Objective G went well. The students definitely have prior knowledge on graphing. Objective H went well with the exception of finding density-using slope. It’s not that they couldn’t do it, but that they failed to use the slope method. Instead, they were using the density equation, which hadn’t even been shown in class yet. It had to be clarified that when the question stated “using the graph” that slope must be used, if this is not stated they may use 55 the method of their choice. Day 14: Explain what density means and show how to calculate density using problem-solving strategies. Pairs-Check Worksheet: Density Individual assignment: Objective I, page 35, 34-38. Students are to turn it in when the assignment is completed. Day 15: Laboratory Investigation: Using a Graph to Find Area. This is a lab that is in the chapter. The objectives are: Measure the mass and calculate the are of rectangular samples of poster board. Graph mass and area data, drawing a “best-fit” line through the origin. Interpret a graph to find the area of an irregularly shaped sample of poster board. Homework: Read and outline chapter 1, part 4, pages 24- 29. I had never done this lab before. It worked well. It was done in the students base groups. They divided the responsibilities up among the group members (with some suggestions from the teacher). It was a great way to do an alternative assessment on objectives G and H. Part 4: Exploring Matter Objective J: Discuss how properties of matter can be used for identification of matter. 56 Objective K: Distinguish between chemical and physical changes. Objective L: Use models to explain different properties of solids, liquids, and gases. Day 16: Shareabout: Chapter 1, part 4. In base groups: Objectives J, K, and L, page 36, 39—51. Turn in when complete. Day 17: Experiment 1.2: In this experiment, students will make observations of chemical and physical changes with the common substances sugar, baking soda, salt, iron filings, vinegar, water, and wood alcohol. Students will also become familiar with the physical properties of these substances. In this experiment, it is the responsibility of each student to construct a data table for recording observations. The students worked in pairs to collect data for this lab. However, it was the responsibility of each student to construct their own data table, as well as answer their own questions as homework. I felt that this lab was less difficult and, therefore, one of the better labs to have students try on their own. The only students that did poorly were those that didn’t take the time to answer the questions at the end of the lab. Day 18: Quiz on Objectives J-L. Learning Guide using Numbered Heads Together. Day 19: Chapter 1 Test. 57 Appendix C-2 Chapter 2: Describing Matter Part 1: Defining Mixtures and Pure Substances Objective A: Discuss properties and techniques that can be used to determine whether matter is a mixture or a pure substance. Objective B: Summarize how decomposition of a pure substance can be used to differentiate between elements and compounds. Objective C: Compare and contrast compounds and mixtures, using the law of definite composition and the law of multiple proportions. Objective D: Distinguish between elements and compounds on the submicroscopic level using the atomic model. Assignment 1-1: Outline Part 1. This was assigned after Chapter 1 test. Day 1: Stump the Teacher. Sharearound: Go to the left. Demonstration: Distillation. Day 2: Assignment 1-2: Base Groups, pp. 49 1—9. Report 58 answers to class. Reporter will be chosen randomly (Numbered Heads Together). Assignment 1-3: Start in Base Groups and finish the rest individually at home, pp. 75, Objectives A-B, 1—5. Day 3: Students will be given 10 minutes to work briefly in their base groups before the assignment is collected. Laboratory Investigation: Household Substances and Chemical Change. In this lab students will perform experiments on common household products. They will identify chemical changes and identify the differences between the substances based on their observations. They will also classify some substances as pure substances or mixtures, based on their data. The laboratory investigation was very exciting for the students. The chemical reactions were very easily recognized and very messy. I think that using substances that the students see in their homes makes the lab even more beneficial. Day 4: Sharearound: Groups will share their responses to the questions on the lab. Assignment 1-4: Base groups, pp. 75—76, Objectives C-D, 6- 11. Report answers to class. Reporter chosen using Numbered Heads Together. Assignment 1-5: Homework is to outline chapter 2, part 2. 59 Part 2: Symbols and Names of Molecular Compounds Objective E: Use chemical symbols to represent elements and the formulas for compounds. Objective F: summarize information about the elements and their properties form the periodic table. Objective G: Identify the names of binary molecular compounds from their formulas. Day 5: Stump the Teacher. Sharearound: Sections 2.6-2.7 Elemental Bingo: This is a game using bingo cards with the symbols of the elements on them. The purpose of the game is to reinforce the learning of the element's names and symbols. Throughout Chapter 1, students were given a list of elements to learn, slowly adding more and more. The complete list is found in the book on pp. 50. Assignment 2-1: pp. 60, 13-16. Individually with a periodic table with symbols only. Day 6: Discuss Sections 2.8-2.9 Practice Problems pp. 60, 10-12,17,18, on the board with the students. Assignment 2-2: Pairs-Check: Naming and Writing Formulas for Binary Compounds. Day 7: Assignment 2-3: Base groups, Objectives E-G, pp. 76, 60 12—20. Sharearound: Reporters chose using Numbered Heads Together. Quiz 1: Part 2, Objectives E-G Part 3: Formulas and Names of Ionic Compounds Objective H: Predict the formulas of ionic compounds from their formulas. Objective I: Identify the names of ionic compounds from their formulas. Objective J: Recognize the charge of an ion from a chemical formula. Day 8: Discuss 2.10-2.11 Predicting Formulas. Use magnetic models to help get the idea across. Practice Problems, pp. 63, 19-22, pp. 64, 23-25, pp. 67, 26- 29. Do with students on the board. Stress the importance of writing down the steps to this process. Assignment 3-1: pp. 71, 38, 41. Individually complete the problems, then get into base groups and compare answers. If not everyone has the same answer then the group needs to figure out who went wrong and how to fix it. Day 9: Discuss 2.12-2.13 Naming Ionic Compounds and Predicting Ion Charge. Practice Problems, pp. 69, 30-33, pp. 71, 34-37. Assignment 3-2: pp. 71, 39, 40, 42. Individually, then 6] check in base groups. Pairs-Check: Ionic Compounds Day 10: Assignment 3-3: Numbered Heads Together, pp. 77, Objectives H-J, 21-25 Day 11: Quiz 2: Part 3 Objectives H-J Pre-lab questions in base groups. Report answers. Day 12: Experiment 2-1: Law of Definite Composition In this lab, students become familiar with the use of crucibles. They also obtain practice in calculations involving mass ratios. The experimental results demonstrate the law of definite composition. Day 13: Synthesis questions from the lab. Numbered heads together. In this lab, students were having difficulties handling the crucibles, which resulted in a loss of a few of them. They also had some difficulties understanding how to use the mass ratio of magnesium to oxygen to determine the formula of magnesium oxide. Day 14: Assignment 3-4: Learning Guide for Chapter 2. Individually, then Sharearound. Day 15: Chapter 2 Test, individually. Homework: Outline Chapter 3 Part 1. 62 Appendix C-3 Chapter 3: Chemical Reactions and Equations Part 1: Identify Chemical Reactions Objective A: Recognize the occurrence of chemical reactions by macroscopic observations. Objective B: Define energy and differentiate between the two kinds, kinetic and potential. Objective C: Interpret the meaning of symbols in chemical equations. Objective D: Describe chemical reactions by writing balanced chemical equations. Objective E: Explain the difference between exothermic and endothermic reactions and recognize equations that represent them. Day 1: Sharearound Chapter 3 part 1. Focus on 3.1, 3.2. Assignment 1-1: Numbered heads together, pp. 115 Objectives A_B’ 1-4. Day 2: Discuss 3.3-3.6 (3.6 show how to recognize a balanced equation, but save the balancing for the next lesson). Practice problems: pp. 96, 3—6, 11 63 Assignment 1-2: Numbered heads together, pp. 115, Objective C, 5-11. If not finished in class, finish at home. Day 3: Experiment 3-1: Observing Chemical Changes. Prelab questions: Base groups, numbered heads together. Experiment In this lab, students will have the opportunity to observe four different signs of chemical reactions: color change, temperature change, gas formation and precipitate formation. The lab emphasizes observation skills, with encouragement to think about how some observations can be quantified. This lab is also the first lab for students to use some of the microchemistry lab materials. Day 4: Analysis and Conclusions Synthesis Use numbered heads together to go over the results and answers to the questions. Day 5: 3.6 Balancing equations. Students must take notes and write down all their steps for credit on their assignment. Practice problems: pp. 95, 1,2 Assignment 1-3: Worksheet: A Balancing Act, done individually. Sharearound. Pairs-Check: Balancing Equations 64 Day 6: Assignment 1-4: pp. 117, Objective D, 12-19, in base groups. They will have just the class period to finish. Suggest that they divide up problems, work them out on a separate sheet of paper and write the final answers on the group paper that will be collected. Day 7: Pass back group work. Look at the incorrect questions and make corrections. Ask/Answer questions. Assignment 1—5: Numbered heads together: pp. 116, Objective B, 20-23. Day 8: Quiz 1: Objectives A-E, Chapter 3 part 1. Homework: Outline Chapter 3 part 2. Part 2: Regularities in Chemical Reactions *Objective F: Classify reactions as belonging to one of the five general types of chemical reactions. *Objective G: Predict the products of a reaction from the reactants. *Objective H: Differentiate between decomposition reactions and dissociation. **Objective I: Determine by using an activity series whether a single replacement reaction will occur. (* Shows optional objectives and ** shows advanced topics. 65 If time is running short the advanced topics will not be covered.) Day 9: Sharearound Chapter 3 part 2. Make sure all students have examples of the five types of reactions. Assignment 2-1: Numbered heads together, Worksheet: Types of Reactions. Day 10: Individually, pp. 117 Objective F, 24-27. When completed, get in base groups to compare answers. If they don’t agree they need to come up with an answer everyone can agree on. Report answers to class. Lecture: Predicting Products of Reactions Homework: Assignment 2-2, pp. 111, 15. (Students will have difficulties with the assignment.) Day 11: Have students write answers from homework on the board and explain how they got the answer. Assignment 2-3: Numbered heads together, pp. 117, Objective G, 28-31. Day 12: Review dissociation and decomposition. Assignment 2—4: Individually, pp. 118 Objective H, 32-33. Lecture: Determining if a single replacement reaction will occur using an activity series. Homework: Assignment 2—5, pp. 111, 16-18. 66 Day 13: Have students write answers on the board and explain. Assignment 2—5: Numbered heads together, pp. 118, Objective 1, 34-36. Day 14: Quiz 2: Chapter 3, part 2, Objectives F-I. Homework: Write up for Laboratory Investigation, pp. 112- 113. Day 15: Laboratory Investigation: Identifying a Chemical Reaction In this lab, students will look for evidence that a chemical reaction has taken place, distinguishing between mixing, a change of state, and a chemical reaction. The students find this lab a lot of fun, for it involves their first test for hydrogen gas. It does a wonderful job helping students identify a true chemical reaction versus mixing or a change of state. Day 16: Learning Guide, Chapter 3. Numbered heads together. Day 17: Chapter 3 Test. 67 Appendix C-4 Chapter 4: Molar Relationships Part 1: Counting Atoms Objective A: Define the term mole and describe how it is used in chemistry. Objective B: Explain and calculate molar mass. Objective C: Calculate equivalents among grams, moles, and number of particles. Day 1: Sharearound, Chapter 4, part 1. Lecture: Molar Conversions, factor-label method. Practice problems (together on the board): pp. 126, 129, 131, 132, 1-8. Homework: pp. 135, 9-22. Day 2: Have students show work and answers to problems on the board. Pairs-Check: Molar Conversions. Homework: pp. 156 Objective A, 1-4. (Students will have difficulties with number 4.) Day 3: Show problems 3-4 on the board. Numbered heads together: pp. 157, Objectives B—C, 5-22. Day 4: Quiz 1: Molar Conversions. Experiment 4-1, Prelab questions. 68 Day 5: Experiment 4—1: Determination of the Empirical Formula for a Compound In this lab, students will synthesize a compound and determine its composition quantitatively. The major difficulty in this experiment is in eliminating the water of hydration from the magnesium chloride. It will be difficult for students to recognize if the hydrate was overheated or underheated, so time must be spent going over the percent error and teach the students to reason logically as to what caused the error. Overall, the results are very good and the lab introduces some new techniques. Day 6: Calculations. Analysis and Conclusions. Day 7: Lecture: Concentration and Molarity Practice problems: pp. 140, 24-25. Homework: pp. 141, 28-31. Day 8: Have students show work and answers on board. Pairs-Check: Molarity. Homework: pp. 157-158, Objective D, 23—26. Day 9: Correct homework. Do problems on board if needed. Quiz 2: Molarity. Day 10: Lecture: Percent Composition. 69 Practice problems: pp. 144, 32-33, pp. 153, 41,42 Homework: pp. 158, Objective F, 31-33. Day 11: Have students put work and answers on the board. Quiz 3: Percent Composition. Lecture: Significant digits. Make sure students get all of the rules written in their notes. Homework: pp. 153, 48-51. Day 12: Go over pp. 153, 48-51 on the board. Numbered heads together: pp. 158, Objective H, 39—41. Homework: Worksheet: Significant Digits. Day 13: Sharearound: Worksheet on Significant Digits Quiz 4: Significant Digits. Review Sheet: Chapter 4, Individual Day 14: Chapter 4 Test. 70 Appendix C-5 Chapter 5: Stoichiometry Part 1: Quantitative Meaning of Equations Objective A: Determine the number of moles of reactants or products involved in a chemical reaction, using mole ratios. Objective B: Calculate the masses of reactants or products in a reaction, given data in either moles or mass. Objective C: Interpret data to determine the amounts of reactants or products involved in replacement reactions using Molarity. Day 1: Lecture: Determining the number of moles of reactants and products using mole ratios. Practice problems: Together on the board, pp. 163, 1-2, pp. 173, 9-10. Pairs-Check: Mole-Mole Homework: pp. 186, Objective A, 1-5. Day 2: Have students go to the board to show work and answers for pp. 186. Lecture: Mole-Mass Calculations Practice problems: pp. 168, 3-4. Lecture: Mass—Mass Calculations Practice problems: pp. 170 5-6, pp. 173, 11—12. 71 Homework: pp. 187, Objective B, 6-10. Day 3: Work in base groups to look over pp. 187. Numbered heads together: finish Objective B, 11—14. Day 4: Lecture: Molarity and Replacement Reactions Practice problems: pp. 173, 7—8, 13-14. Pairs-Check: Molarity and Replacement Reactions. Wrap-Up: Where would Stoichiometry be useful and why? Day 5: Numbered heads together: pp. 188, Objective C, 15-19. Day 6: Quiz: Chapter 5, part 1, Objectives A-C. Prelab Questions: Experiment 5—1. Day 7: Experiment 5—1: Moles and Mass in a Reaction. This experiment gives students an opportunity to test stoichiometric predictions against actual experimental results. When the laboratory procedures are carefully done, the results verify the molar relationships in the chemical equation and provide added assurance that the equation does, in fact, quantitatively describe the chemical reaction. Day 8: Finish Experiment 5-1. Calculations and Synthesis. (May need to review some problems for the students.) 72 Day 9: Choose groups, randomly, to answer lab questions on the board. Compare group results and analyze where the differences could have occurred. Part 2: Adjusting to Reality. **Objective D: Determine the limiting reactant in a chemical reaction to predict the amount of product that can be formed. **Objective E: Calculate percent yield of a product using the ratio of experimental mass produced to theoretical mass predicted. (Objective D and E are both considered advanced topics. I will not cover Objective D, but will offer it for extra credit.) Day 10: Lecture: Percent Yield. Practice problems: pp. 182, 19-20. Numbered heads together: pp. 188, Objective E, 26—28. Day 11: Laboratory Investigation: Conservation of Mass, pp. 184. In this laboratory investigation, students will perform three reactions and observe how the law of conservation of mass is valid under ordinary conditions. They will do this by comparing the masses present before the reaction with the masses present after the reaction. 73 Day 12: Compare group results and discuss the questions. Review Chapter 5. Day 13: Chapter 5 Test. 74 Appendix D EXPERIMENT 1-1 Working in the Chemistry Laboratory Objectives 1. Demonstrate mastery of essential laboratory techniques and procedures, as well as a familiarity with laboratory equipment. 2. Apply safety precautions to laboratory procedures. 3. Observe the reaction between limewater and carbon dioxide. 4. Interpret the results of two chemical reactions. Materials Bunsen burner centigram balance flame spreader funnel filter paper stirring rod 6-mm glass tubing 2 125-mL Erlenmeyer flasks one-hole stopper to fit flasks two-hole stopper to fit flasks rubber or plastic tubing ring stand and ring wire gauze thermometer 2 250-mL beakers spark lighter or matches triangular file 100-mL graduated cylinder metric ruler marking pen cloth gloves funnel holder folded cloths or towels glycerin laboratory aprons safety goggles 0.5M hydrochloric acid magnesium ribbon sodium carbonate calcium hydroxide distilled water Prelab 1. Read the introduction and procedure before you begin. 2. Answer prelab questions 1-9 on the Report Sheet. 75 Procedure Part 1 1. Put on your safety goggles and laboratory apron. Before you begin to work with your Bunsen burner, compare it to the pictures of the two common lab burners. Most Bunsen burners are constructed in a similar fashion. There is an inlet for the gas, an adjustment for the flow of gas, and an adjustment for the flow of air. A proper mix of air and gas will yield a faint blue flame for maximum heat and minimum soot. Identify the gas adjustment and the air adjustment on your burner. Before you light the burner, turn the air adjustment to allow as little air as possible. Before you light the burner, check to make sure that all students nearby are wearing their safety goggles. Lighting the Bunsen burner is a one-person job. Have a match or spark lighter ready before you turn on the gas. Light the burner by turning on the gas and holding the spark lighter or lighted match above the barrel of the burner. Adjust the flame to a blue color by changing the flow of air and the flow of gas. Turn off the burner and go on to the next part of the experinment. Part 2 In order to make the limewater solution, you must be able to use a lab balance. A balance must be zeroed before it is used to find masses. Place the balance on a level table and find the zero-adjusting screw. Adjust the balance to the zero point. The balance you are using probably has three beams. In order to properly record the mass, you must add up the masses indicated by the riders on the three beams. Chemicals are measured in a container or on paper, never directly of the pan or platform of a balance. Place a clean, dry 250-mL beaker on the pan of the balance and determine the mass of the beaker. Record the mass on the Report Sheet. 76 Place approximately 3 g of calcium hydroxide in the beaker and find the mass of the beaker plus the calcium hydroxide. Record this mass on the Report Sheet. Use the graduated cylinder to measure 175 mL of distilled water and add the water to the calcium hydroxide in the beaker. For this experiment, it is not important to know the exact amount of liquid, so you do not have to measure exactly. Stir the solution with a stirring rod. Calcium hydroxide is difficult to dissolve. Heating the solution will speed the process. Set up a ring stand with a ring and a wire gauze. Heat the solution gently, stirring constantly for approximately 5 to 10 minutes. Not all of the solid will have dissolved, even after heating. Turn off the burner. Remove the beaker form the ring stand and place it on the lab table. Let the solution cool and settle while you set up a funnel to filter the solution. CAUTION: The beaker will be hot. Use a thick, folded cloth as a hot pad to protect your fingers. The wire gauze and iron ring will also be hot; do not touch them until they have cooled. Filter paper is normally in the shape of a circle. Fold it carefully in half and then in quarters. Open the paper so that it forms a cone and place it in the funnel. Moisten the filter paper with a few drops of distilled water. The filter paper should fit snugly and adhere to the funnel. Pour the solution down you stirring rod into the funnel. Allow the clear solution to filter into the beaker below. You will use the clear limewater for parts 4 and 5. Put the filter paper and any solid it may contain into the place designated by your teacher. Part 3 1. Obtain a piece of glass tubing 50-cm long. Use a metric ruler and a marking pen to mark the tubing where it is to be cut into two 20-cm pieces and one 10-cm piece. Place the tubing on a firm surface. Use a triangular file and make a single firm stroke across the tube to scratch it at the place where you want to cut the glass tubing. Put one or two drops of water on the scratch. Then hold the tube with the scratch away from you, with 77 both thumbs behind, one on each side of the scratch. Place your elbow against your sides; push with you thumbs against the tube while twisting you wrists outward. The glass should break cleanly at the scratch. CAUTION: To avoid cuts, wear cloth gloves when you break glass tubing. Repeat this process at the other mark on your tubing. You should now have two 20-cm pieces and one lO-cm piece. To smooth the ends of the glass tubing, a technique called fire polishing is used. Light the burner and adjust the air to get a blue flame with an inner core. Place the end of one piece of tubing in the flame at the very top. Rotate the tubing slowly and continuously so that the heating is even. While rotating the tubing, lower the end slowly until it is just above the tip of the inner core. You will quickly notice the end of the tubing soften and become smooth. Do not leave the glass in the flame too long or the end of the tube will close. Fire polish the ends of each piece of tubing. CAUTION: Be careful with hot glass tubing. It looks the same when it is hot as when it is cool. Place the hot end of the tube on a wire gauze or other fireproof material and wait for the tubing to cool. Turn off the burner and place the flame spreader on the top of the burner. The flame spreader allows you to evenly heat a longer section of glass and bend the glass tubing more easily. Hold one of the 20-cm pieces of tubing with both hands and place the center of the tubing in the flame while rotating the tubing. Continue to rotate the tubing until you notice that the tubing is softening. Immediately remove the tubing from the flame and quickly bend it 90 degrees in on smooth motion. Repeat with the other 20-cm piece. Allow the bends to cool. Slide one of the 20-cm pieces and the 10-cm piece of tubing through the holes of the two-hole stopper. Put the other 20-cm piece into the one-hole stopper, again using glycerin. Save both stoppers fitted with glass tubing for Parts 4 and 5. CAUTION: Always protect both your hands with thick, folded cloth pads when inserting glass tubing into the hole in a stopper. Use glycerin as a lubricant. NEVER force the tube into the hole; if it does not slide 78 easily, call your teacher. If you have to adjust the tube later to slide it up or down in the stopper hole or if you wish to remove the tube, be sure to protect your hands with thick, folded cloth pads. Call your teacher if the stopper does no move easily. Part 4 1. Place just enough clear limewater into a 125—mL Erlenmeyer flask so that the end of the glass tubing is just below the surface of the liquid when a two-hole stopper is inserted into the flask. Put the stopper on the flask tightly. Gently blow into the end of the bent tubing. You exhale carbon dioxide (among other gases). Continue to exhale into the tube until you observe a change. Record your observations on the Report Sheet. Pour the cloudy limewater into the container designated by your teacher. Part 5 1. Attach a short piece of rubber or plastic tubing to the ends of both 90 degree bends and set up your two flasks as shown by your teacher. Rinse the flask you used in Part 4 and fill it with fresh, Clear limewater to the same level as before-just above the end of the bent tubing. In the other flask, place about 35 mL of 0.5M hydrochloric acid. Using a thermometer, measure the temperature of the acid and record it on the Report Sheet. Rinse the end of the thermometer with water after removing it from the acid. Obtain a piece of magnesium ribbon from your instructor. Carefully drop the magnesium into the acid and quickly place the stopper on the top of the flask. Record your observations on the Report Sheet. As soon as the reaction stops, remove the stopper and measure the temperature of the acid. Record it on the Report Sheet. 79 10. Pour the acid and limewater into containers designated by your teacher and dispose of any leftover magnesium as directed. Rinse all glassware and repeat steps 2,3,and 4. Record the temperature on the Report Sheet. Obtain about 2 grams of sodium carbonate. Carefully transfer the sodium carbonate into the acid and quickly put the stopper on the flask. Record your observations on the Report Sheet. As soon as the reaction stops, remove the stopper and measure the temperature of the acid. Record it on the Report Sheet. Dispose of any leftover acid, limewater, and sodium carbonate as directed by your teacher. Before leaving the laboratory, clean up all materials and wash your hands. 80 EXPERIMENT 1-2 Identifying Chemical and Physical Changes Objectives l.Observe and define properties of some common substances. 2L Recognize physical and chemical changes in some common substances. I3.Construct a data table to record and interpret observations. Materials 6 small test tubes scoopula test tube rack stirring rod glazed paper safety goggles lO-mL graduated cylinder laboratory apron sodium hydrogen carbonate sodium chloride sucrose iron filings distilled water 1M acetic acid methanol Prelab 2. Read the introduction and procedure before you begin. 3. Answer prelab questions 1-5 on the Report Sheet. 4. Read the Analysis and Synthesis questions, and construct a Data Table on a separate sheet of paper for use in recording the observations in this experiment. Procedure 6. Put on your safety goggles and laboratory apron. 7. Each of the solid reagents will be tested in the same way. Choose one of the solids and obtain enough to have three pea-sized samples. Use a scoopula to remove the solid from the container and place it on a sheet of glazed paper. Carefully observe the solid and note your observations. 8l 10. ll. 12. Set up three small test tubes in the test tube rack and label each with the name of one of the liquids. Place 5 mL of each of the three liquids in its test tube. CAUTION: Methanol is flammable and toxic. Make sure there are no flames in the room. Do not get any methanol in your mouth; do not swallow any methanol. Place a pea-sized sample of the first solid in each test tube. Observe any immediate change over the first minute. Let the samples remain for ten minutes and observe the test tubes again. While you are waiting for the ten minutes to pass, repeat steps 1-4 with a second solid sample. Use your remaining three test tubes. Finish your observations on the first two solids, then repeat the whole procedure for the next two solids. Once you have recorded your observations, clean up all materials and wash your hand thoroughly. 82 EXPERIMENT 1-2: Report Sheet Identifying Chemical and Physical Changes Prelab Questions 1. 2. 5. Give two examples of a physical change and of a chemical change. What is the purpose of observing the materials in the test tubes immediately and then again after waiting ten minutes? How can you tell if a temperature change has occurred if you do not have a thermometer? What signs of chemical change would you look for in this experiment? Write, in your own words, the purpose of this experiment. Data and Observations Complete your Data Table before you answer the questions. Analysis and Conclusions 1. Summarize the chemical changes you have observed in this experiment. Color changes: Formations of gases: Change of temperature: Formation of precipitates: Summarize the physical changes you observed in this experiment. How would you describe the difference in appearance among the three white solids? 83 What are the common names for each of the following substances? Sodium chloride: Sodium hydrogen carbonate: Sucrose: Acetic acid: Methanol: Synthesis 1. What is the chemical name of the substance formed in the slow reaction that takes place when iron filings are mixed with water? 2. How could you recover sucrose or sodium chloride once it has dissolved in water? 3. What are the chemical formulas for each of the following substances you used in this experiment? Iron Sucrose Acetic acid Sodium hydrogen carbonate Sodium chloride Methanol Water 4. How many different elements are in the above substances? 5. Three of the compounds are composed of the same three elements combined in different ways. What does this tell you about the makeup of any compound? 6. Think about some fast and slow reactions you have observed in the last 24 hours. Give one example of a slow reaction and one example of a fast reaction, other 84 than the chemical reactions you observed in this experiment. 85 EXPERIMENT 2-1 Law of Definite Composition Objectives 1. Observe a reaction between magnesium and oxygen. 2. Calculate a ratio of mass of magnesium to mass of oxygen. 3. Measure masses carefully to obtain accurate results. Materials crucible and lid crucible tongs medicine dropper centigram balance pipestem triangle ring stand and ring Bunsen burner and lighter wire gauze sandpaper or emery cloth safety goggles laboratory apron magnesium ribbon distilled water Prelab 1. Read the introduction and the procedure before you begin. 2. Answer prelab questions 1—7 on the Report Sheet. Procedure 1. Put on your laboratory apron and safety goggles. 2. Obtain a piece of magnesium ribbon from your teacher. If the surface is not shiny, use a piece of sandpaper or emery cloth to shine the surface. 3. Obtain a clean, dry crucible and cover. Find the mass of he crucible and cover and record it on the Report Sheet. 86 10. 11. Roll the magnesium in a loose coil and place it into the crucible. Find the mass of the crucible, cover, and magnesium. Record it on the Report Sheet. Set up the ring stand, ring, Bunsen burner, and pipestem triangle. Begin heating the crucible gradually with the lid completely on. Heat slowly by moving the flame around underneath the crucible. Remove the heat temporarily if a large amount of smoke comes out of the crucible. After about four minutes of direct heating with no smoke, remove the lid slightly. Heat the crucible to redness for four minutes. Finally remove the lid completely and heat strongly for four more minutes. Turn off the Bunsen burner and put the lid back on the crucible. Allow the crucible and cover to cool to a temperature low enough so that you can touch the crucible. Find the mass of the crucible, contents, and cover. Record the mass on the Report Sheet. CAUTION: Hot crucibles and magnesium can cause burns. Handle the hot crucible with tongs and place the hot crucible on the wire gauze to cool. Add ten drops of distilled water. Smell cautiously, noting any odor. Set up the crucible for heating again. Reheat for four more minutes with the lid on. Let the crucible cool once again. Find the mass of the crucible, cover, and product. Record it on the Report Sheet. Compare the masses found in steps 7 and 9. If the masses do not agree within 0.03 g, reheat the crucible for four minutes, cool, and find the mass. Repeat until the last two masses agree within this range. Before leaving the laboratory, clean up all materials and wash your hands thoroughly. 87 Experiment 2-1: Report Sheet Law of Definite Composition Prelab Questions Why is it so important to begin this experiment with a clean and dry crucible? What is the purpose of making sure the outside of the magnesium ribbon is clean and shiny? With what element or elements does the magnesium combine when it is heated in the crucible? In the procedure, you are asked to reheat the crucible repeatedly until the last two masses agree within 0.03 9. What is the purpose of this reheating? If you were to combine 80 g of oxygen with some hydrogen, how much hydrogen would you need to completely use up all of the oxygen? Suppose a compound of sodium and chlorine is formed in the ratio of 1.54 g of chlorine for each gram of sodium. How much sodium would you need to completely react 45.0 g of chlorine? In your own words, write the purpose of this experiment. Data and Observations Data Table 1 Mass of crucible and cover Mass of crucible, cover, and Mg Mass of crucible, cover, and product 13t time (before adding water) Mass of crucible, cover, and product 2m’time Mass of crucible, cover, and product 3w‘time 88 Calculations For each of the calculations, show your work in the space provided and record your results in Data Table 2. 1. Find the mass of the magnesium that reacted. 2. Find the mass of magnesium oxide that was produced. 3. Find the mass of oxygen that reacted. 4. Find the ratio of the mass of magnesium to the mass of oxygen. 5. The accepted ratio for the mass of magnesium to the mass of oxygen is 1.52. Calculate your percent error using the formula: 1.52 — your ratio X 100% 1.52 Data Table 2 Mass of magnesium that reacted Mass of magnesium oxide produced Ratio of magnesium to oxygen Percent Error Analysis and Conclusions 1. Check with other members of your class to see how your results compare. Do you see any trends? 89 2. How would your results be affected if all the magnesium did not react? Synthesis 1. Use your textbook to determine the formula for the magnesium oxide formed in this experiment. 2. Use the accepted ratio to determine what mass of magnesium would combine with exactly with 16.0 g of oxygen. 3. Suppose you tried to combine 42 grams of magnesium with 45 grams of oxygen. a. Which of the two substances would have some left after the reaction? b. How much magnesium oxide would be formed? 4. When one pound of gasoline (made up of compounds of hydrogen and carbon) is burned in an automobile, approximately 3 pounds of carbon dioxide, CO2, is given off. Carbon dioxide is one of the gases contributing to global warming. What information from this experiment helps to explain how one pound of gasoline can give off approximately 3 times as much C02? 90 Experiment 3-1 Observing Chemical Changes Objectives 1. Observe chemical and physical changes. 2. Present and explain observations of changes accurately and completely. 3. Identify and use appropriate lab equipment necessary to quantify observations. 4. Recognize patterns in observations. Materials centigram balance spot plate small test tubes test tube rack stirring rods lOO-mL beaker 10- or 25-mL graduated cylinder safety goggles laboratory apron ammonium chloride sodium bicarbonate calcium carbonate calcium chloride soluble starch 1M strontium chloride solution 1M sodium sulfate solution 1M acetic acid solution 0.05M sodium hydroxide solution iodine solution phenolphthalein solution 0.1M sodium hydrogen sulfite solution 0.1M potassium iodate solution Prelab 1. Read the introduction and procedure before you begin. 2. Answer prelab questions 1-4 on the Report sheet. 91 CAO Eyel the Spi Ple: the; Rec: 7' BEIC and Procedure Put on your safety goggles and laboratory apron. In this experiment, you will be asked to make observations. While you are making observations, think about how some of them might be quantified. Be careful to note the phase of the matter you are asked to use. Using the small test tubes, mix the following chemicals in the amounts listed. Stir each mixture with a stirring rod, rinsing the stirring rod each time. a. 2.00 g ammonium chloride + 10 mL of water b. 2.00 g calcium chloride + 10 mL of water c. 2.00 g of sodium hydrogen carbonate + 10 mL acetic acid d. 2.00g of calcium carbonate + 10 mL of acetic acid Using a spot plate, mix the following chemicals in the amounts listed. Stir each mixture and rinse your stirring rod each time. a. 5 drops of sodium hydroxide solution + 1 drop phenolphthalein solution b. 5 drops acetic acid solution + 1 drop phenolphthalein solution c. 5 drops sodium hydrogen sulfite solution + 5 drops potassium iodate solution d. a pea-sized amount of starch + 10 drops of water + 1 drop iodine solution e. 5 drops of strontium chloride + 5 drops sodium sulfate solution CAUTION: Iodine solution is corrosive to skin and eyes. If any of this solution gets in your eyes, use the eyewash fountain immediately. Immediately wash spills and splashes off your skin and clothing using plenty of water. Always report to your teacher when there are spills and splashes. Record all your observations on the Report Sheet. If your results are in doubt, repeat the experiment. Before leaving the laboratory, clean up all materials and wash your hands thoroughly. 92 EXPERIMENT 3-1: Report Sheet Observing Chemical Changes Prelab Questions 1. What piece of lab equipment will you use to measure the following: a. mass b. liquid volume Classify each of the following as liquid, solid, or gas. a. sugar solution b. sugar powder c. water vapor d. carbon dioxide e. salt water f. baking soda g. vinegar Classify each of the following as a chemical or physical change: a. burning match b. ice melting c. water boiling d. ripping a piece of paper e. digestion of food f. rusting of iron In your own words, write the purpose of this experiment. Data and Observations Chemicals Used Observations Ammonium chloride + water Calcium chloride + water Sodium hydrogen carbonate + Acetic acid Calcium carbonate + acetic acid 93 Chemicals Used Observations Sodium hydroxide + phenolphthalein Acetic acid + phenolphthalein Sodium hydrogen sulfite + Potassium iodate Starch + water + iodine solution Strontium chloride + sodium sulfate Analysis and Conclusions 1. Which of the observations could have been repeated in order to quantify the observation? 2. Did you observe any temperature changes? If so, describe them. 3. Describe any color changes you observed. 4. Which combinations produced a gas? 5. Which combinations produced a precipitate? 6. Did any of the combinations result in no reaction? Synthesis 1. Predict the results, based on your observations, of mixing the following pairs of chemicals. Explain why you are making the prediction. If you do not think you have information to make a prediction, explain why. a. magnesium carbonate + acetic acid prediction explanation b. ammonium hydroxide + phenolphthalein prediction explanation c. strontium iodide + sodium sulfate prediction 94 explanation d. hydrochloric acid + sodium hydroxide prediction explanation Suppose you wanted to collect and find the mass of a gas produced in a chemical reaction. How could you do it? Indicators are chemicals that help reveal the presence of certain other chemicals. Two indicators were used in this experiment. What are these indicators and what type of chemical do they identify? Think carefully about indicators in your everyday life. Give one example of an indicator you see outside the chemistry lab and tell what that chemical is used to indicate. 95 EXPERIMENT 5-1 Moles and Mass in a Reaction Objectives 1. Observe the reaction between hydrochloric acid and sodium hydrogen carbonate. 2. Calculate the number of moles of sodium hydrogen carbonate and relate that value to the number of moles of sodium chloride that are produced in the reaction. 3. Calculate the moles of hydrochloric acid used in the reaction, and the moles of water and carbon dioxide produced. 4. Determine the mass of reactants and products. Materials centigram balance Bunsen burner 100-mL graduated cylinder ring stand and ring wire gauze spatula delivery pipet beaker tongs or clamp 2 lOO-mL beakers hot plate (for class) fume hood (for class) lab oven (for class) laboratory apron safety goggles sodium hydrogen carbonate, NaHCO3 1M hydrochloric acid, HCl Prelab 1. Read the introduction and procedure before you begin. 2. Answer prelab questions 1-5 on the Report Sheet. Procedure Part 1 1. Put on your laboratory apron and safety goggles. Obtain a lOO-mL beaker and identify it with your name. Be sure that it is clean and dry. From this point on, you should pick up the beaker with clean tongs. In this way you will avoid adding any additional mass because of what might be on your hands. Find the mass of the dry beaker. Record it on the Report Sheet. Place about 1.5 to 2 grams of sodium hydrogen carbonate in the beaker. Find the mass of the beaker and the contents and record it on the Report Sheet. Place about 30 to 35 mL of 1M hydrochloric acid in another 100-mL beaker. Using a pipet, slowly add about 10 mL of the acid to the beaker containing the sodium hydrogen carbonate. It is important that you add the acid slowly so that the reaction does not force some of the reactants out of the beaker. Continue adding acid until the bubbling stops. Do not add any more acid than is necessary. Place your beaker on the warming tray in the fume hood. When only a few milliliters of liquid remain in your beaker, put it in the oven. Do not let the beaker become dry while the beaker is on the warming tray. Dispose of the leftover acid as your instructor directs. Before leaving the laboratory, clean up all materials and wash your hands thoroughly. Part 2 l. 2. Put on your laboratory apron and safety goggles. Using tongs, remove your beaker from the oven. Allow the beaker to cool. Then measure the mass of the beaker and its contents. Record the mass on the Report Sheet. Dissolve the NaCl in your beaker in water and pour the solution down the drain. Before leaving the laboratory, clean up all materials and wash your hands thoroughly. 97 EXPERIMENT 5-1: Report Sheet Moles and Mass in a Reaction Prelab Questions 1. Which type of scientist makes use of the reaction of carbonates with acids? 2. When sodium hydrogen carbonate reacts with hydrochloric acid, what three products should be produced? 3. How many moles are present in 585 g of sodium chloride? 4. What is the mass in grams of 3.4 mol of carbon dioxide? 5. What is the reason for using tongs to pick up the beaker during this experiment? Data and Observations Mass of beaker Mass of beaker + NaHC03 Mass of beaker + dry solid (part 2, step 2) Mass of beaker + dry solid (part 2, step 4) Mass of beaker + dry solid (after repeated heating if necessary) Calculations 1. Calculate the masses of a. sodium hydrogen carbonate b. sodium chloride 2. Calculate the number of moles of a. sodium hydrogen carbonate 98 b. sodium chloride Write a balanced chemical equation for the reaction. According to the equation, what is the ratio of moles of sodium hydrogen carbonate to moles of sodium chloride? How does your answer to question 4 compare to the results you obtained in question 2? Using the value that you obtained for the number of moles of sodium chloride produced, calculate the number of moles of carbon dioxide and the moles of water that would have been produced. Using the value that you just obtained for the number of moles of sodium chloride produced, calculate the number of moles of hydrochloric acid that would have been used up in the reaction. What are some possible sources of error in the experiment? Synthesis 1. 3. A similar reaction occurs between limestone (calcium carbonate) and hydrochloric acid. Write a balanced equation for this reaction. If 3.00 g of limestone reacted, what masses of the following would be produced? (Show all of your work.) a . calcium chloride tn carbon dioxide c. water Write a balanced equation for the reaction of vinegar (acetic acid, HCHLfib) with baking soda, NaHC03. 99 2. Gra] thr: 3.Int1 Appendix E Laboratory Investigations LABORATORY INVESTIGATION: Chapter 1 Using a Graph to Find Area Objectives 1. Measure the mass and calculate the area of rectangular samples of poster board. 2.Graph mass and area data, drawing a “best fit” line through the origin. 3.Interpret a graph to find the area of an irregularly shaped sample of poster board. Materials centigram balance 4 rectangles of poster board 1 irregular sample of poster board graph paper ruler pencil Procedure l.Obtain four rectangles of poster board from your teacher. 2.Find the mass of each sample of poster board and record the sample number and mass in the data table. 3.Measure the length and width of each sample to the nearest 0.1 cm. Record the measurements under length and width in the data table. 4.Calculate the area of each sample of poster board. 100 EL Obtain an irregularly shaped sample of poster board. Find the mass and record the mass and sample letter in the data table. 6.Plot a graph of mass versus area for your rectangular samples. Use the instructions for graphing provided. Place mass on the y—axis and area on the x-axis. '7.Using your ruler, draw a “best fit” line for your data points. Why should the line on your graph go through the origin? 8.Locate the mass of your irregular sample on the line and determine its area by moving down vertically to the x- axis. Record the area in the data table. 9.To verify the answer, compare your value for the area of this sample with a classmate’s value. Data Analysis Rectangle Mass Length Width Area Code A B C D Irregular sample Mass Area E Conclusions l.Use your graph to find the mass of a poster board sample with an area of 300 cm2. 2.What is the mass of 1 cm3 of poster board? 3.Find the mass of a whole sheet of poster board measuring 71.2 cm by 56.4 cm. 101 4. If you had an unknown sample with a mass greater than the heaviest rectangle, what could you do to the line on the graph to help you find its area? 5.AJ Could you have measured the size of the irregular sheet of poster board with a ruler and calculated its area? Explain. B. How would the calculated value compare with the value from the graph? 102 LABORATORY INVESTIGATION: Chapter 2 Household Substances and Chemical Change Objectives 1. Identify the evidence of chemical change. 2. Identify the differences between two substances, based on evidence from your observations. 3. Classify some substances as pure substances or mixtures, based on your data. Materials 9 13 x 100 mm test tubes baking soda 1 250 mL beaker baking powder test-tube rack vinegar hot plate or bunsen burner household ammonia wooden splints Alka-Seltzer tablets matches distilled or marking pencil deionized water stirring rods mortar and pestle scoops or spatulas Procedure 1. Put on your lab apron and safety goggles. 2. Fill a beaker about one-third full of water and heat it until it comes to a boil. 3. Mark 2 lines on each of 9 test tubes—one at 1 cm from the bottom and one at 4 cm from the bottom. 4. Put baking soda into each of 3 test tubes up to the lower line. Label the tubes A-l, A—2, and A-3. 5. Put baking powder into each of three test tubes, up to the lower line. Label the tubes B-l, B-2, and B-3. 103 10. 11. 12. To test tubes A-1 and B-1, add distilled water to the upper line. Stir with separate glass rods. Test the gas given off in each tube immediately, using a glowing splint. Recall from previous science classes that a glowing splint bursts into flame in the presence of oxygen and is extinguished in the presence of carbon dioxide. Record all your observations on the data table. To test tubes A—2 and B-2, add vinegar to the upper line. Stir with separate glass rods. Test the gas given off in each tube immediately, using a glowing splint. Record your observations on the data table. To test tube A-3 and B-3, add ammonia to the upper line. Stir with separate glass rods. Test the gas given off in each tube immediately, using a glowing splint. Record your observations in the data table. CAUTION: Irritant. Do in hood. Do not inhale funoa of ammonia. Heat test tubes A—1 and B-1 in the beaker with the boiling water. Has any additional fizzing occurred? Has any additional dissolving occurred? Record these observations in the data table. Heat test tubes A-2 and B-2 in the beaker with the boiling water. Make observation as before. Again record our observations in the data table. Crush one or two Alka-Seltzer tablets with a mortar and pestle. Put the powder into each of 3 test tubes to the lower mark. Label the tubes C-1, C—2, and C—3. Test the Alka-Seltzer in the same way as the baking soda and baking powder. Add water to tube C-l, vinegar to C-2, and ammonia to C-3. Remember to add ammonia in the hood. Record your results in the data table. Heat the tubes in the beaker of boiling water, and record our observations again. HM Data Table l> Iw IO Water with out heat With heat Vinegar without heat With heat Ammonia Data Analysis 1. What happened when you added the glowing splint to the gases? 2. Which conditions were best for the fizzing of baking soda? The fizzing of baking powder? Can you identify the gas given off? 3. List the ingredients labeled on the packages of baking soda and baking powder. Conclusions 1. Which tests gave evidence of a chemical change? 2. a. Basing your conditions on the results shown in the data table, which baking product would you say Alka- Seltzer most resembles? Explain your answer. b. Obtain the ingredient label for Alka-Seltzer. Was your conclusion correct? 3. Can you determine if baking soda and baking powder are mixtures or pure substances? Why or why not? Recall from Chapter 1 that dissolving is a physical change that can be used to distinguish among substances. 105 4. Write a hypothesis based on your data to explain how you could differentiate between baking soda and baking powder if you were given an unknown sample. 106 LABORATORY INVESTIGATION: Chapter 3 Identifying a Chemical Reaction Objectives 1. Observe several possible chemical reactions. 2. Identify observations that indicate that a chemical reaction has taken place. 3. Distinguish between mixing, a change of state, and a chemical reaction. Materials Lab apron aluminum foil Safety goggles NaOH pellets or lye 125 mL Erlenmyer flask vinegar with one-hole distilled water stopper baking soda thermometer 1.0M copper(II) sulfate trough solution 6 test tubes vegetable oil solid stopper for ammonia water test tube spatula or tongs candles matches wooden splints Ziploc plastic bag Procedure 1. 2. Put on your lab apron and safety goggles. Roll a 10 x 10 cm piece of aluminum foil into a ball and place it in a 125 mL Erlenmeyer flask. Using your spatula or tongs, add one or two pellets of sodium hydroxide or a few crystals of lye. CAUTION: Sodium hydroxida pellets aro vary corrosivo to oyoa, skin, and clothing. If any aodium.hydroxida got: in your oyoa, uao tho oyowaah fountain innadiataly. Do not try to 107 pick up or nova apillod.pollota. Innadiataly wash apillod.pollota and roaidnoa of! your skin or clothing. Add a few drops of water to the aluminum and sodium hydroxide mixture and put the one-hole stopper on the flask. Fill a trough with water and place the flask completely under water. Collect the gas in a test tube by placing the test tube under water and inverting it so hat the opening is over the flask. Stopper the test tube when filled with gas and remove it from the trough. Test the gas by placing a glowing splint inside the tube and observing the splint. Record your observation on the data table. Add 5 mL of vegetable oil to 5 mL of water in a test tube. Shake well. Place a thermometer in the test tube. Record your observations and the initial temperature in the data table. Wait a minute and record the temperature again. Record the temperature of 10 mL of vinegar in a test tube. Add 10 mL of ammonia water. Observe the temperature again and record your data. Add 5 mL of a 1.0M copper(II) sulfate solution to 5 mL of ammonia water in a test tube. Record the initial temperature. Wait a minute and record the temperature again. Light a candle and make observations. Record your observations on the data table. Place 10 mL of vinegar in a Ziploc plastic bag and add a scoop of baking soda. Close the bag until the reaction subsides. Open the bag and immediately test the gas by placing a glowing splint inside the bag and observing the splint. Record your observations on the data table. 108 Data Analysis Step 4 5 Conc Observations Temp. 1 Temp. 2 lusions 1. In which steps were you simply mixing substances? In each case, how could you have separated the substances in the mixture? In which steps did you observe a physical change (change of state)? Basing your answer on your observations, which trials do you think were chemical reactions? What observations led you to your conclusions? In which steps was a gas produced? Can you name the' gases? Explain why some of the gases were not the result of a chemical change. What chemical change occurred in step 8? What physical change occurred? What gas do you think causes a glowing splint to burn? KW LABORATORY INVESTIGATION: Chapter 5 Conservation of Mass Objectives 1. Measure the mass of reactants before a reaction and the mass of products after a reaction. 2. Calculate the percent difference of mass before and after the reaction. 3. Evaluate the validity of the law of conservation of mass under ordinary laboratory conditions. Materials Balance 0.1M sodium sulfate solution 150 mL beaker 0.1M strontium chloride Erlenmeyer flask solution 10 mL graduated cylinder 0.5M hydrochloric acid 2 13 x 100 mm test tubes magnesium carbonate 2 corks to fit test tubes sodium nitrate 18 x 150 mm test tubes NO. 2 rubber stopper for Large test tube Small watch glass Paper for massing Procedure Part 1 1. Put on your safety goggles and laboratory apron. 2. Place 2.0 mL of 0.1M sodium sulfate solution in a 13 x 100 mm test tube. Place 2.0 mL of 0.1M strontium chloride in another test tube. Cork and label each. 3. Place the corked test tubes with their contents in a 150 mL beaker. Determine the total mass of the solutions, test tubes, beaker, and corks. Record the total mass in your data table. 4. Pour the strontium chloride solution into the test tube containing the sodium sulfate solution. Observe the chemical reaction. H0 Place the product test tube with cork and the empty test tube with cork into the 150 mL beaker. Mass the two test tubes, the beaker, the two corks, and the reacted solution. Record this combined product mass in your data table. Part 2 6. 10. Place 10 mL of water in the large test tube and stopper it. Place approximately 5 g of sodium nitrate solid on paper. Find the total mass of the test tube, water, stopper, sodium nitrate solid, and paper. Record this total mass on the data table. Transfer the sodium nitrate solid to the water, recork the test tube, and shake the mixture until the sodium nitrate dissolves. Find the total mass of the test tube, sodium nitrate solution, stopper, and paper. Record this total mass on the table. Part 3 11. 12. 13. 14. Mass 1 g of magnesium carbonate on a small square of paper. Place 10 mL of 0.5M hydrochloric acid in a 125 mL Erlenmeyer flask and cover with a small watch glass. Find the total mass of the flask, watch glass, hydrochloric acid, and the magnesium carbonate on the paper. Record this total mass on the data table. CAUTION: Hydrochloric acid in corrosivo to skin and oyoa. 'lhah of! spill: and.oplaahaa. If hydrochloric acid got: into your oyoa, uao tho ayowaah fountain innadiataly. Carefully transfer the solid magnesium carbonate from the paper to the hydrochloric acid and place the watch glass on top. After the reaction has subsided, find the total mass of the flask, watch glass, product contents of the flask, and the paper. Record this total mass. 1“ Data Analysis Experiment Total Mass Before Total Mass After Part 1 Part 2 Part 3 1. Calculate the change in mass for each part of the experiment. Record your results on the table below. 2. Calculate the percent change in mass and record your results in the table below. (mass after — mass before) x 100 = % change mass after Experiment Change in Mass % Change in Mass Part 1 Part 2 Part 3 3. How could you revise the experiment to improve the result? 4. Calculate how many grams of gas must have been produced in the third part. 5. What effect does the leftover strontium chloride in the test tube have on your results in Part 1? H2 Conclusions 1. Basing your answer on the data and calculations, did you find the law of conservation of mass to be valid in all three parts? 2. If your data did not confirm the law in every part, can you suggest a reason? H3 Activities of Science A B C D E mung Matt A B C D E Appendix F-l Unit Test Results COOPERKHVE 1$% 59% 29% 9% 9% COOPERAHVE W% 29% 29% 1T% 1T% ChanmdFundkmsademmflmm RIDGE!) Mberdamngps 111000) Skkhhnnfly NOON) COOPERKHVE 33% 3r% 25% 9% T% OOOPERKHVE W% 39% 29% 29% 19% COOPERKHVE 4f% 29% 1&% 1f% 1V% 'WUWNHONAL 3% 23% 49% 29% 9% TRADHWONAL T% 29% 29% 29% 19% TRNWTKnul 26% 49% 2V% 19% 9% . TRADITIONAL H4 19% 29% 19% 2T% 2V% 'HUEWHONAL AommksofiSdaxn 70% OR BETTER BELOW 70% Deufihthbflu' 70% OR BETTER BELOW 70% Appendix F-2 70% or Better on Unit Tests COOPERATIVE LEARNING TRADITIONAL 89% 70% 1 1% 39% COOPERATIVE LEARNING TRADITIONAL 65% 58% 34% 42% ChunmdfkwcmmsandEmMmoms 70% OR BETTER BELOW 70% MbhwRdamxmmps 70% OR BETTER BELOW 70% COOPERATIVE LEARNING TRADITIONAL 98% 85% 2% 15% COOPERATIVE LEARNING TRADITIONAL 63% 52% 37% 48% H5 Appendix F-3 Graphs of 70% or Better on Unit Tests Activities of Science COOPERAHVELEAHMNG TRAmmONAL I 70% OR BETTER E BELOW 70% H6 Describing Matter COOPERATIVE LEARNING TRADITIONAL I 70% OR BETTER E BELOW 70% 117 Chemical Reactions and Equations COOPERATIVE LEARNING TRADITIONAL I 70% OR BE‘ITER E BELOW 70% 118 Molar Relationships 70% T 60%‘ 50%., 40% , 30% » 20% ~ 10%, 0%- COOPERATTVE LEARNING TRADITIONAL I 70% OR BETTER E BELOW 70% 119 APPENDIX G-l SCIENCE SURVEY QUESTION SET I Use the scale at the right to answer the following questions. Use 5 as highest score. 1. I like science 5 4 2. I worry about my work in science 5 4 3. I am curious to learn about science 5 4 4. I think science is fun and interesting 5 4 5. I feel I am smart in science 5 4 6. I prefer hard, challenging work in science5 4 7. I do well at my work in science 5 4 8. I plan to have a career in science 5 4 120 Appendix G—2 I LIKE SCIENCE I 59%1 49%d~ 20% 10% - 9%~ 5 4 3 2 1 I BEFORE I AFTER 121 I WORRY ABOUT MY WORK IN SCIENCE 4 3 2 I BEFORE I AFTER 122 I AM CURIOUS TO LEARN ABOUT SCIENCE 50% r 30% I. 20% if 10% 4 5 4 3 2 1 I BEFORE I AFTER 123 ITHINK SCIENCE IS FUN AND INTERESTING I BEFORE I AFTER 124 I FEEL IAM SMART IN SCIENCE I BEFORE I AFTER 125 I PREFER CHALLENGING WORK IN SCIENCE I BEFORE I AFTER 126 I DO WELL IN SCIENCE 50% ‘- 40% (7 30%'- 20% 10% 7» I BEFORE I AFTER 127 I PLAN TO HAVE A CAREER IN SCIENCE 30% 20% 0% I BEFORE I AFTER 128 APPENDIX H-l SCIENCE SURVEY QUESTION SET II Use the scale at the right to answer the following questions. Use 5 as the highest score. “I do work in science class"? a. to get work done on time b. to memorize facts and information c. to learn vocabulary and definitions d. to receive rewards from parents e. to do better than other students f. to use science to understand the world g. to please my parents h. to get good grades i. to be sure my ideas are scientifically correct j. to show that I am a smart person k. to do well in class activities 1. to please my teacher 129 Appendix H-2 GET WORK DONE ON TIME 59%w— 49%48 30% .1... 29%~~ 19%4» 9%“ 5 4 3 2 1 I BEFORE I AFTER BO MEMORIZE FACTS AND INFORMATION 10% I BEFORE I AFTER 131 LEARN VOCABULARY AND DEFINITIONS 50% 20% 5 4 3 I 2 1 I BEFORE I AFTER 132 RECEIVE REWARDS FROM PARENTS 40% « 30% -- 20% 10% 0%1 5 4 3 2 1 I BEFORE I AFTER 133 DO BETTER THAN OTHER STUDENTS 60% T 5 4 3 2 1 I BEFORE I AFTER 134 USE SCIENCE TO UNDERSTAND THE WORLD 5 4 3 2 1 I BEFORE I AFTER 135 PLEASE MY PARENTS 4 3 2 I BEFORE I AFTER 136 60% ~1— 5o% ~~ 40% + 30%1L 20% ~~~ 10% T 0%“ GET GOOD GRADES 4 3 I BEFORE I AFTER 137 2 + --o- SURE IDEAS ARE SCIENTIFICALLY CORRECT 4 3 2 I BEFORE I AFTER 138 SHOW I AM A SMART PERSON 20% 1 5 4 3 2 1 I BEFORE I AFTER I39 DO WELL IN CLASS ACTNITIES I 20% 10% I BEFORE I AFTER I40 PLEASE MY TEACHER 20% I I I I | 10% 0%, 4 3 2 ‘ 1 I BEFORE I AFTER I41 Appendix I-l Self Test Survey I'm always like this I'm usuafly like this I'm sometime like this I'm seldom like this I'm never like this 1. Self-reliant and self— confident 2. Realistic about my strengths and weaknesses 3. Feel responsible for own activities; don't make excuses and blame others 4. Set challenging but possible ls 5. Plan carefully and intelgqently 6. Take personal obstacles into account 7. Take world obstacles into account 8. Kncwhowtofindanduse help 9. Keep working toward goals 10. Check progress 11.Like to achieve and dislike not achieving 12. Want todoa betterjob in betterways 13. Useanachievedgoalasabesisfornewgoals 142 Appendix I-2 Graphs of Self Test Survey Results 69%T 50% .1.— 40% .. 30% -» 29%“ 19%+ 9%1 AUNAYS Self-reliant and Self-confident I {:- _‘ ‘ w ‘ {it 3 ...R .315 'n x ..15 Tess-B " . We ‘51» .- 3 "(4 s} x. e D ‘i' . _. .x"<~ .& s , -.:.v le'l- 5444-: lllllli USUALLY SOMETIMES SELDOM NEVER w BEFORE llllllll AFTER 143 Realistic about strengths and weakness 60% T- 50% + 40% 30% I” II 20% 1» 35:35:11?" ~ 4 - "1’"? "11355344. USUALLY SOMETIMES SELDOM BEFORE IIIIIIII AFTER 144 Feel responsible for own activities USUALLY SOMETIMES SELDOM NEVER BEFORE lllllll AFTER 145 Set challenging but possible goals 50% T 40% i ”my. .mnfimx . . x .. ..........H éfififivw mm“. . .nfl .. 4 USUALLY SOMETIMES SELDOM . t e ..{nuau . .zz? a n k. f . - 0%~ NEVER ALWAYS 146 Plan carefully and intellegenfly 60% I 50% . 40% 1'- 30% * illt'lgir -: 20% , . 10% -» 0% 1 USUALLY SOMETIMES SELDOM BEFORE [1111111 AFTER 147 Take personal obstacles into account o“.- .3". .4 u. . .A .. 33%”? .. ...-f: 1”. . ...AN 4 rczfln... a .- (”une- ..x u g .4 50% -1 40% .- 30% JE USUALLY SOMETIMES SELDOM NEVER ALWAYS BEFORE lllllll AFTER 148 Take world obstacles into account USUALLY SOMETIMES SELDOM NEVER ALWAYS .1... A m E R O ...r. B I49 40% 20% 0%4 Know how to find and use help ALWAYS USUALLY SOMETIMES SELDOM NEVER BEFORE [Illllll AFTER 150 keep working toward goals 60% 4. 50% ~~ I 40% 4 30% T SIT-ER S. TR 20% ~~ STIR" 4.; \ ffifit' a x! .‘ ~ '- t‘szé‘".fl.:fih 9‘95: 10% + IIIIIE ALWAYS USUALLY SOMETIMES SELDOM NEVER 0%1 BEFORE MIIII AFTER 151 Check progress 50% w— 40% 30% 20% «E HI” ‘1 10% T ALWAYS USUALLY SOMETIMES SELDOM NEVER 0%- BEFORE lllllll AFTER 152 Like to achieve & dislike not achieving 70% T 60% 1» 433'” . 'J-w 50% -~ 40% 4 30% 4» 133.. a. «14.x \ 1444‘. 2‘ ‘e c ._. 4% 20% + 10% TIIIIIHIIII . ,. ALWAYS USUALLY SOMETIMES SELDOM NEVER 0%1 BEFORE lllllll AFTER 153 better ways Want to do a better job in USUALLY SOMEIIM ES SELDOM NEVER ALWAYS m A m m 0 F m 154 Use achieved goals as basis for new 50% T 40% 30% 4 I 20% 1 10% 1* "h a . fl ALWAYS USUALLY SOM EIIM ES SELDOM NEVER ‘3‘?“ : git-la 0%1 BEFORE llllllll AFTER 155 BIBLIOGRAPHY 156 BIBLIOGRAPHY Ames, Carole. 1992. Classrooms: Goals, Structures, and Student Motivation. JOurnal of Educational Psychology. 84(3): 261—271. Ames, Carole & Archer, Jennifer. 1988. 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Sweeny, J. 1992. School Climate: The Key to Excellence. NASSP Bulletin. 69-73. Wang, M.C., Haertel, G.D., & Walberg, H.J. 1994. What Helps Students Learn? Educational Leadership. 74-79. 158 "IIIIIIIIIIIIIIIII