1. General

At this point in the quarter, it would be very advisable to review your IR and NMR notes from lecture. You are expected to have mastered these topics by the time the final exam comes around.

Note for the teaching assistant: the students should start the reflux first and can take the test during this period of time

2. Experiment

Safety note: Concentrated sulfuric acid is very corrosive. Wear nitrile gloves when you transfer it! Avoid spills on your clothes!

For this week’s experiment it is important that the glassware is dry. Why?

Be careful when you do the extractions with sodium bicarbonate. Mix the two layers with a spatula or a small glass rod (especially the first time!). Don't forget to vent the centrifuge tube when you shake it.

Add only a small amount of drying reagent, otherwise you will loose a lot of your product in the next transfer.

If you only have a small amount of crude product, pre-weigh your Hickman head.


3. Things to think about

a. Why do you use an excess of acetic acid in the experiment?

b. Do you expect the esterification to go to completion? How can you improve the yield of the ester using the same reagents?

c. What is the function of concentrated sulfuric acid in the experiment?

d. Why do you have to wrap a cold paper towel around the air condenser?

e. Why do you have to heat the mixture to a boil?

f. How does the refractive index change with the temperature? How would impurities influence the value?

g. How many signals do you expect to observe in the ¹³C{¹H}-NMR spectrum of the following compounds: acetone, acetic acid, isopentyl alcohol, sulfuric acid, sodium bicarbonate?