Modifications to Panacetin Experiments 2 & 3
1. You will be given an unknown sample. Weigh it and use all of it.
2. For “Separation of Aspirin” on the middle of page 32, we will be using 5% sodium
bicarbonate solution (NaHCO3), instead of 1M sodium hydroxide. Sodium hydroxide
sometimes reacts with the ester group of aspirin.
3. For “Isolation of the Unknown Component” on the bottom of page 32, we will do the
following:
a. Weigh your clean and dry 100 mL round-bottomed flask.
b. Transfer your dichloromethane layer form the separation of Aspirin to the round-
bottomed flask.
c. Put a label on your cork ring with your name on it.
d. Take your round-bottomed flask and the cork ring to the rotary evaporators in the
back of the room, and have your dichloromethane removed. If the rotary
evaporators are in use, leave them there.
e. When your dichloromethane has been removed, reweigh the flask to determine
the mass of the unknown.
4. After you have isolated the unknown in step 3 above, scrape it out into a 125 mL
Erlenmeyer flask. Any remaining unknown can be removed from the flask by rinsing the
flask with a few mL of boiling water.
5. Be sure to allow your aspirin and unknown to dry thoroughly before you weigh them and
determine their melting point ranges.
