November 4, 2009: CH301 Random Musings—Every Problem for the Rest of the Course 0. Exam 2 results. As mentioned last week, the results for the second exam were very good with an average of about 83 for the regular exam, a spectacular result, and an average of 75 for the make-up, which is also very good. We tossed three questions total from each exam including the solids question from both tests because I made misleading statements about what to study and it turned out that the problems we used had variable questions and answers. We also tossed two questions from each exam that were misprogrammed. Those of you who didn’t get extra points after the regrade on these misprogrammed questions, shouldn’t have, because if you got the right answer the first time you either guessed, or were wrong and didn’t deserve it. A comment on the fairness of the test. One of the things that makes professors want to run and hide is when students claim that a make-up test was harder. Usually fairness can’t be proven, but in fact, using Quest, it can. Expected grade (data base historical data) Actual grade Exam 2 65.8 83 Exam 2 makeup 66.7 75 What this tells me is that you are a very good class and that the two tests were similar in difficulty. 1. Here is a hint when writing to express concern about “unfair questions”--just because you got something wrong doesn’t make the question unfair. If you are going to write and explain the unfairness or ambiguity, you have to do it from a level that is larger that yourself. Neither Travis nor I want to hear about why you got a question wrong, when the reason you got it wrong is that you didn’t know the material. Please understand: we kill questions that are misprogrammed and we kill questions that have ambiguous (multiple) answers based upon the strategies for problem solving that might be available to you. We do not kill questions, or get points back, because of your inability to learn the material. 2. Southpark does thermodynamics. You don’t produce two college age males without watching a lot of Southpark. So you can imagine my dismay, when about seven years ago, mid-November, 2002, while watching epidsode 612, The Death Camp of Tolerance, I was deeply saddened to hear the following, utterly shocking statement from Mr. Garrison: [South Park Elementary, day, Garrison's class. Mr. Garrison enters, having previously set up a chemistry experiment on the teacher's desk.] Mr. Garrison: Okay, children, let's take our seats. Uh, apparently, none of you tried to get me fired yesterday, so I guess we're just gonna have to go on and learn more today. [sits on a corner of the desk] Now who can tells me what happens to water when we heat it up in the Bunsen burner? Butters: It evaporates. Mr. Garrison: Good, Butters. Now if we take the glass tube of the Bunsen burner, we can also see how other things react. [takes the tube in hand and walks over to Mr. Slave] Evaporation is an exothermic reaction, so let's look at an endothermic one….. NOOOOOOOOOOOOO!!!!!!!! You see, the problem is Mr. Garrison wasn’t “being the system”. If you will “be the system” you realize that water evaporating is an endothermic process, because you are adding heat to the system (ΔH is positive.) He should have said Evaporation is an endothermic physical processAnyway, you know it is hard enough trying to get students to “be the system” without having it contradicted by cable television. 3. Signing up for my class—no good deed goes undone. I have been gracious enough to provide current students with priority access. You fill out a form, I add you to the class. I even posted the notice that you didn’t need to do anything—you would be added during registration periods on Thursday and Friday, just make sure you don’t sign up for another CH302 course and make sure that you leave the time open. So what happens: Over 100 of you have e-mailed frantically to ask, in every way possible, about why you aren’t in the course yet, and 65 of you have either signed up for another CH302, signed up for a class during my time, haven’t gotten your bars cleared, or are over maximum hours. I don’t know what to say other than that we will make one more effort to add you to the course starting tomorrow at 8 am. If you haven’t taken care of the problem, we will give your seat to one of the 300 people who have e-mailed asking to be placed in the course. If you have a question about this, please e-mail me tonight and explain your situation. 4. Schedule for the rest of the course. Is the semester really almost over? 20 H 11/5 Statistical Thermodynamics 21 T 11/10 Internal Energy 22 H 11/12 Internal Energy Quiz 5 23 T 11/17 Entropy 24 H 11/19 Entropy 24 T 11/24 Free Energy and pie and ice cream Quiz 6 25 T 12/1 Free Energy W 12/2 Exam 3 Lectures 18-25 5. Quiz 5 is next Thursday with the question types presented below: • Bomb calorimeter calculation • Hess’ Law and calculating enthalpy changes • Work calculation • Predicting entropy change • Temperature dependence of reaction spontaneity • Statistical thermodynamics calculation of E and S 6. A Worksheet 11 will be posted this weekend to help you prepare for the quiz. A practice quiz 5 will be posted this weekend in the Portal on Saturday and a TA practice quiz will be posted on Monday or so. 7. Question Types. What better way to spend the Thanksgiving holidays than studying, and what better way to study than to sink those question types for the class into your brain before you begin to study. So here you go,Quiz 6, Exam 3 and Final Exam question types for the rest of the semester, reproduced at the bottom of the musings. 8. My discussion sessions next week will be in the classrooms because of the quiz. 9. Extra Credit Opportunities. As promised, here is an opportunity to add 1% to your total course grade. Extra Credit 1. The Instructions. • I want you to teach a science-hater something interesting about chemistry that you have learned in this class. The person you teach has to say to you, “gee, I had no idea chemistry was that interesting” when you have finished (you can make them say it even if they don’t mean it.). You can choose what you teach but I would recommend that it be something of interest and utility, like the complications of cooking at high altitude
View Full Document
Unlocking...