Chem 201 Archive – Alan Shusterman

Day: October 11, 2009

  • pKa of Bromcresol Green lab – feedback

    I made two marks on each lab. Report indicates whether the written document was prepared properly. In-lab/Models indicates whether you followed directions reasonably well during the two lab periods.

    A number of “unsatisfactory” Report grades were issued. Most of these were related to the graphs. Perhaps a graph was missing. Or perhaps the wrong data was plotted on one of the axes. Or sometimes the data table was missing. (There were many other smaller omissions, like missing lab partner name or missing/substandard reference for published value of pKa, but I didn’t mark off for these.) If your Report grade was “unsatisfactory”, submit a new and improved report to me by Friday, Oct 16, and I will reconsider your grade.
    (more…)

  • HW #4 feedback

    First, a confession … I made a mistake on the answer sheet that I posted last Friday. The very first problem asks for the reaction product of HI + 1-butene in the presence of peroxides. The correct (?) answer is 1-iodobutane (the anti-Markovnikov product), but I drew 2-iodobutane (the Markovnikov product) on the answer sheet. I have corrected and posted a new answer sheet, but because my readers had already marked up the homework assignments, ignore any “wrong” marks.

    Second, the great physicist Albert Einstein once said something like this in reference to theories of physics, “Everything should be made as simple as possible, but no simpler.” The same should be said about structural formulas, resonance structures, and chemical reactions.
    (more…)