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Meeting #13
General Announcements
1. The next quiz will be administered on Wednesday, May 16, 2007 at 12 pm. It will cover the Grignard reaction, esterification and nitration reaction.
2. Please look start looking for a partner for the last project. Your partner should be in a different time slot than yourself e.g. if you are in T/R morning section, your partner should be in section in the T/R afternoon section or in the W/F afternoon section. The proposal will be due on May 25, 2007 at 5 pm.
3. If possible both reactions (esterification and nitration) should be carried out in this lab. This will give you more time to recrystallize the final product and get better quality crystals. The final product has to be turned in to the TA by May 18, 2007.
Homework questions
1. Referring to the Esterification carried out in the lab, answer the following questions. Show chemical equations where appropriate.
a. Why is it imperative to dry the benzoic acid thoroughly before carrying out the esterification?
b. What would happen if the student decides to use benzoic acid in excess?
c. What is the function of the sulfuric acid in this reaction? Show appropriate intermediates here.
d. Why is the reaction mixture refluxed for about 60 min?
e. After the reaction is terminated, the reaction mixture is cooled and poured into water. Explain briefly why.
f. How does the student know that he can discontinue the extraction with sodium bicarbonate?
2. Referring to the Nitration reaction carried out in the lab, answer the following questions. Show chemical equations where appropriate.
a. What are the functions of sulfuric acid in the reaction?
b. Why is important to control the temperature of the reaction mixture carefully?
c. A student attempts to recrystallize the crude product from hot methanol. What would he observe?
d. What are the most important changes in the IR spectrum going from methyl benzoate to m-nitro methylbenzoate?