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Acetylsalicylic Acid Lab

Acetylsalicylic Acid
September 15, 2005
September 23, 2005

OBJECTIVES
The objective of this lab experiment is to prepare aspirin (acetylsalicylic acid) by reacting salicylic acid and acetic anhydride.

INTRODUCTION
This purpose of this lab was to prepare aspirin using its basic components: salicylic acid and acetic anhydride. Salicylic acid and acetic anhydride, along with an acid catalyst, react to form acetylsalicylic acid (aspirin) and acetic acid. In this reaction, the hydroxyl group on the benzene ring in salicylic acid reacts with acetic anhydride to form an ester functional group. The acetylsalicylic acid crystallizes as the solution cools and begins to come out of the solution. The acetylsalicylic acid is further purified through recrystallization with ethyl acetate.

MATERIALS USED:
Test Tubes Pasteur Pipette
Salicylic acid acetic anhydride
Sulfuric acid 125 mL Erlenmeyer flask
Scale Water Hot water bath
Ice Bath Buchner Fünnel
1% Ferric Chloride
Ethyl acetate Glass Rod
Iodine Aspirin Tablet
Commercial Aspirin tablet

METHODS
Part A
1. 2.0 g of salicylic acid was placed in a 125 mL Erlenmeyer flask.
2. 5.0 mL of acetic anhydride was added to the flask and five drops of concentrated sulfuric acid was also added.
3. The flask was swirled to dissolve the salicylic acid.
4. The flask was placed in a hot water bath for ten minutes.
5. The flask had to be placed in an ice bath briefly and the sides were scratched with a glass rod until crystallization occurred.
6. 50 mL of water was added and the flask was returned to the ice bath for another five minutes. This allowed for more crystallization to occur.
7. The solution was placed in vacuum filtration using a büchner funnel for five minutes. Distilled water was added to the flask to flush solution off the sides of the flask to be poured into funnel for filtration.
8. The remaining product was allowed to air dry and was weighed. The product weight was 2.88 g.
9. The...