Week 5 Problem Set 30 BL (Esterification Reaction)
Useful Link: Refractometer
ATTN: answers to the below questions are due at the start of your lab period; these answers should be part of your pre-lab write-up.
1. Extraction with sodium bicarbonate
a. Why is it necessary to be careful in the beginning?
b. Could you replace it by NaOH solution?
2. Why do you have to reflux the reaction mixture?
3. Refractive index
a. Which information do you get from the refractive index?
b. Which parameters influence the refractive index? In which way?
4. A student refluxes a mixture 33.3 g of propionic acid, 10 mL of methanol and 1 mL of concentrated sulfuric acid for two hours. After the work-up, the student isolated 14 mL of the ester.
a. Determine the yield of the reaction. Show all the calculations.
b. How could the student improve the yield?
c. What would happen if he forgets the add the sulfuric acid?
5. Do questions 4, 7, 8 and 11 on p. 140 in Landgrebe.
6. How many signals do you expect to observe in the 13C{1H}-NMR spectrum of the following compounds: benzoic acid, m-cresol, naphthalene, 1,3,5-Trichlorobenzene, toluene, acetone
7. Which information do you get from the DEPT spectrum and the HMQC spectrum of a compound?