Aspirin Preparation

Running head: Aspirin Preparation
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Title: Synthesis of Aspirin
Purpose: The experiment was meant to prepare aspirin from acetic anhydride and salicylic acid.
Experimental procedure:
About 2g of salicylic acid was weighed in a 125ml Erlenmeyer flask. The flask was first completely dried to remove any traces of water since acetic acid reacts with water. Secondly 5ml of acetic anhydride from the dispenser and 5 drops of phosphoric acid were added into the mixture. The mixed solution was then heated gently for about 10 minutes on a hot plate. The heating was done in manner so as not to boil the solution and in the process ensure complete dissolution of the solid. The flask was then carefully removed from the hot plate and 2ml of water added to the flask. The reaction was then left to occur for some time after which another 40 ml of water was added.
The flask was then cooled in ice bath for ten minutes as the vacuum filter apparatus was being prepared. The crystals were vacuum filtered and the flask rinsed with a small amount of water. The rinsing water was poured through crude aspirin crystals then transferred to a small beaker to await the subsequent experiment.
19050499110Experimental set up
Figure 1. Aspirin synthesis setupResults:
Table SEQ Table \* ARABIC 1.Yield of acetylsalicylic acid
Compound

Theoretical yield

Actual yield

Percentage

Acetylsalicylic acid

2.06g

1.76g

72%

Mass of crude product = (Mass of flask plus crude product) - (Mass of empty flask)
93.49g-91.73=1.76 crude product.
Discussion:
The table shows how much acetylsalicylic acid was produce as compared to the amount of salicylic acid used. Given that the ratio of is 1:1 the acid used must equal acetylsalicylic acid recovered. However this is not the case and ca...