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. a. Can you use 5% NaOH solution during the work-up?
b. Why is it advisable to use a a conical vial or centrifuge tube here for the extraction part?
c. How does refluxing the reaction mixture help the product to form?
d. Which reactant is used in excess here and why?
2. A student refluxes a mixture 38.5 g of salicylic acid, 20.0 mL of ethanol and 2.0 mL of concentrated sulfuric acid for three hours. After the work-up, the student isolated 37.5 mL of the ester.
a. Determine the yield of the reaction. Show all calculations.
b. How could the student improve the percentage yield of this reaction?
c. The student observes refractive index of nD15= 1.5240. Which conclusion can he draw from this observation?
3. Extraction Theory (Hint: See appendix of reader)
a. Construct two different flow diagrams to separate 1,12-diaminododecane, salicylic acid and naphthalene.
b. Construct a flow diagram to separate m-cresol, naphthalene and 3-pentanone.
c. When performing extractions why is it important to use a solvent quantity that is higher then 10% of the solution to be extracted?