CH302 Random Musings: March 22, 2007 1. Welcome back from Spring Break. One of the things that will amaze those of you new to college is how rapidly the last half of the spring semester disappears leading to final exams. For many of you it will be the most challenging academic experience of your life if you are in a bunch of science courses. I still vividly recall my own experience that first spring semester trying to do well in chemistry, calculus, biology, chemistry lab and biology lab plus two liberal arts courses. I don’t think I slept the week I had five finals in three days. So just strap on a seat belt and enjoy the ride. It will make what comes later in college seem like a walk in the park. 2. Starting three years ago I decided that second round of children would not grow up thinking that spring break was when you stayed home and did yard work. So beginning with New Orleans, and then the Smokey Mountains, and now New York, my spring breaks involve carting a very large family around in a minivan somewhere far from home. Below are photos of Sam and Nathan ordering $2 hot dogs in Central Park, and Maddie on a horse drawn carriage in the middle of the city realizing: 1) that her dad is a loser and 2) that she will be back to New York, to stay, as soon as she can. 3. The only other thing to add is that by far the most fun I had in New York was driving the streets of the city like a maniac, in a minivan, and realizing I was so good at driving in New York because of my time spent driving through the intersection of 24th and Speedway between classes, every day for the last 20 years. 4. On Worksheet 8 there is a typo that I can’t fix easily, so I tell it to you here. The problem is number 2, about NaH2PO4 and in the answer key the Na+ is not considered in the charge balance. Also, if you consider Na+, there are 7 unknowns, so there are 7 equations needed, and the one additional equation is a mass balance for Na: CNaH2PO4 = [Na+]. Sorry for the confusion. 5. I want to cut off the new material for the second exam so only half of electrochemistry will be on it. So what I discuss in lecture today is last stuff to show up on exam 2. This should give you a solid week of bounding exactly what you need to learn rather than having to cram last minute information on electrochemistry in all at once. I know this will disappoint some of you and I apologize.6. I am posting for your use, an approximation of the 30 question types on Exam 2 that will be given on April 2—I reserve the right to make some minor adjustments early next week. Exam 2: 30 question types 1. Identifying acid and base strength 2. Calculating simple buffers 3. Identifying buffers (after neutralization) 4. Ranking acidity and basicity based on equilibrium constants 5. Buffer capacity 6. Buffer neutralization calculation 7. Identifying features of a titration curve 8. Identifying features of a titration curve 9. Titration of strong acid and strong base 10. Titration of strong acid and strong base (equivalence point) 11. Titration of weak acid/base with strong base/acid (buffer region) 12. Titration of weak acid/base with strong base/acid (equivalence point 13. Estimating solubility from Ksp 14. Calculating molar solubility from Ksp 15. Common ion calculation 16. Approximations: deriving acid base equations from equilibrium theory 17. Approximations: simplifying polyprotic acid calculations 18. Setting up complex equilibrium problems 19. Mass and charge balance 20. Equilibrium expressions for a polyprotic acid 21. Equilibria Calculations: dilute solutions 22. Equilibrium Calculations: sulfuric acid case 23. Equilibrium Calculations: weak polyprotic acids 24. Balancing redox reactions (simple) 25. Balancing redox reactions (in acid or base) 26. Ranking oxidizing and reducing strengths 27. Ranking oxidizing and reducing strengths 28. Assigning EC cell nomenclature 29. Assigning EC cell nomenclature 30. Calculating Ecell at standard conditions 7. Extra Credit 1. Reminder. Due on April 1 at 3 am. To earn 1% of your course grade that you can add to your point totals for the semester, complete the assignment below and follow the specific instructions for submission provided in the last few musings. IMPORTANT. You must title the extra credit: Spring break extra credit followed by your uteid. The details have been published twice in the musings, no need to do it again, but those of you thinking of not doing it must either have really solid As or not care what grade you get. A piece of advice: this is where I lower the cutoffs for grades at the end of the year, so do you want to be a part of the lower cutoffs or not? 8. Undergraduate Research Forum. I’m big on doing and since I am not your father so you can listen to me when I say that your education here at UT will be mightily improved if you take the bold step of deciding to engage in an active learning environment. The best such environment, of course, is found in one of the hundreds and hundreds of research labs where people are curing cancer and figuring out how old the universe is. On Friday, April 20 right outside this room, about 150 of your undergraduate peers in the College will be displaying their efforts at original scientific research. You should wander through and be amazed that people just like you are doing all kinds of science that you are just beginning to fathom right now. Use this as motivation to get started yourself—I believe it is the principle reason to go to a large university like UT—surely it isn’t the machine graded exams. For more information on the poster session: http://cns.utexas.edu/students/ohris/research. 9. Extra credit number 2 is coming soon. Okay, so some of you remain unconvinced that you should spend time staring at posters about science that might make you feel inadequate compared to your peers. Well what if I offered up 1% of your grade to go to the poster session, find a poster you like, talk to the person standing in front of it for 5 minutes, and then going home and e-mailing me about your experience. More details to follow but the procedure for getting credit will be the same. (For those of you who can’t go to the poster session, an alternative bonus opportunity is to walk through a science building on campus on the upper floors, staring at thewalls. You will see scads of research posters that are up for your perusal. Just take a look at one of those and use what
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