Answers to question #4

a.

Chemistry 220: Introduction to Chemistry (Prelab for Cyclohexanone… and Warm-up 8-28). This course is the first semester of the sophomore level Organic Chemistry sequence. It serves chemistry majors, biology majors, and health science students (pre-med, pre-vet, etc.) Students are introduced to the fundamental aspects of bonding and structure as it pertains to the molecules of carbon. Included in this discussion are concepts of shape, polarity, and stereochemistry. These concepts are used to predict the reactivity of the various functional groups and classes of organic compounds. Students are also expected to learn the IUPAC system of nomenclature for all of the major classes of organic compounds. General reaction patterns of organic molecules are studied, including concepts of reaction mechanism, free-energy changes, and chemical kinetics. In lab, students gain experience with a variety of techniques including extraction, distillation, crystallization, and chromatography. Hands-on use of instruments, including IR, HPLC, NMR and GC-MS is an integral part of the course. All of these techniques are used in a variety of synthesis and isolation labs, many of which have a discovery component to them. It is expected that students take an active role in asking and answering questions in lab.

Chemistry 320: Intermediate Organic Chemistry (Prelab for EAS Rates and Radical Warm-up) This course is the second semester of the sophomore level Organic Chemistry sequence. It serves chemistry majors, biology majors (these students are not required to the second semster), and health science students (pre-med, pre-vet, etc.). In this course, students make use of their previous introduction to the fundamental aspects of the bonding and structure of carbon molecules and apply these to carbonyl compounds, aromatic compounds, carbohydrates and amino acids. Included in this discussion are concepts of shape, polarity, and stereochemistry. . Building on the introduction of these classes of compound, we also cover the major classes of large biological compounds, including concepts of protein folding and conformation. Finally, we cover two other classes of organic reactions, radical reactions and pericyclic reactions. The lab is a continuation of Organic I with students expected to demonstrate a stronger sense of independence.

b, c, d.

8-28 Warm-up: This assignment was due on the 2^nd day of class. During the first session, we covered/reviewed ideas of bonding and Lewis structures. Students were reading sections of the book dealing with empirical formulas, molecular formulas etc. During the previous class period we spent time drawing Lewis structures for compounds containing no more than 4 carbons, and applying rules of bonding to insure that the structures were realistic. This warm-up exercise provided an assessment of student mastery of the previous day’s work, and their comprehension of the day’s reading assignment. In questions 1 and 2, students were asked to use the material they “learned” during the first day of class. For question 1, it was a direct application of drawing Lewis Structures, but students had to address a larger molecule than they did the previous day. From experience, I know that drawing organic molecules and getting the correct number of bonds to each atom is a struggle for some students. I also know that students who struggle with this concept will struggle with the whole course. My aim for this question was to start to get a feel for which students would need more help early on so that they could have the best chance of mastering the material for the course. I also asked students to describe the structures in words getting them used to thinking in English to make sure they truly understand the concept. For question 2, students needed to use some reasoning skills to come up with an appropriate answer. We had covered the idea of polarity (which relates to electron density) in the previous class, but this question is looking at totally new material. My goal was to have students practice applying old information to new material. Much of organic chemistry is looking for connections and using previous material to apply to new situations, and I felt that the earlier I started this with students, the better off they would be. The multiple choice question dealt with the day’s reading assignment. It was a direct application, and was just designed to see if students had a basic understanding of some of the material.

Prelab for Cyclohexanone Reduction: This was the third lab of the semester. During the “lecture” portion of the class, students should have gained experience with drawing Lewis structures, shape, etc. We had also covered some basic ideas of mass spectroscopy. This assignment in part assessed student preparedness for the laboratory assignment, and hopefully helped to head off questions in lab, by asking students to think about problems ahead of time. Questions 2 and 3 also help students do a better job of writing up the lab later because they’ve already had to think through some of the concepts. Question 1, was separate from the other questions, in that it asked students to draw a structure (of a compound used in the lab) and analyze that structure in ways organic chemists typically do. This gets back at the issues I talked about for 8-28 warm-up – students need to know how to do this, or they typically don’t pass the course.

Radical WarmUp: This warm-up is from the middle of Organic II (Intermediate Organic Chemistry), and after students had received a fairly thorough (two and a half days) introduction to radical chemistry. My goal was to assess student mastery of this topic on the day we were scheduled to go on to the next topic. Questions 1 and 3 get at some of the fundamental principles involved in radical reactions. Question 2 asks students to apply ideas from reactions they have covered in class and in the book to a new reaction. It also asks students to put the information in their own words so that they don’t hide behind symbols they may or may not understand. Prior to doing this warm-up, students would have completed one in-class worksheet on this material. This work was done in groups, and the warm-up is supposed to be done individually, although students can consult with each other before they go to the computer to submit their answers.

Rates of Electrophilic Aromatic Substitution Prelab: This is the third lab of the second semester Organic Chemistry course. The answers for questions 1 and 2 are directly from their lab book., and question 3 asks them to make some prediction of the outcome of the reaction based on what they have learned in class. Like all prelabs, this one was designed in part to make sure they read the experiment before coming to class, and that they had some idea of how to deal with the problems they might encounter. I used question 1 in every prelab for the second semester, as I was trying to encourage them to become more responsible for the safety issues. Question 2 is something that almost always comes up during this lab or the students end up leaving assuming their data is good (afterall they took the readings), and they find when they go to plot the data, it gives them poor results. By asking the question ahead of time, I hoped to make them think about the pitfall before they started the experiment and to prevent some students from leaving the lab with inadequate data.