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. Reaction planning
a. Why is an excess of acetic acid used in this reaction?
b. Why is the reaction mixture heated to a boil?
c. Why is sulfuric acid used in this reaction?
d. Which container should be used for the extraction procedure and why?
e. Why are boiling stones added to the reaction mixture?
2. A student refluxes a mixture 37.0 g of phthalic anhydride, 35 mL of ethanol and 5 mL of concentrated sulfuric acid for three hours. After the work-up, the student isolated 35.5 ml of the diester.
a. Show a balanced chemical equation for the reaction.
b. Determine the yield of the reaction. Show all calculations.
c. What would happen if he runs the reaction with phthalic acid instead of phthalic anhydride?
d. The student observes refractive index of nD24= 1.5005. Which conclusion can he draw from this observation?
3. Extraction Theory (Hint: See appendix of reader)
a. Construct two different flow diagrams to separate nitrobenzene, benzoic acid and phenol.
b. Construct a flow diagram to separate a hexanol, naphthalene and N,N-Dimethylaniline.