Sythesis Of Aspirin
After the reaction takes place, water is added to destroy the excess acetic anhydride and cause the product to crystallize.
The aspirin is then collected, purified by recrystallization, and its melting temperature measured.
Use them only in the hood and be sure the hood fan is on! Excess chemicals must be disposed of in the plastic tub of water.
This will convert the acetic anhydride to vinegar and dilute the sulfuric acid.
SAFETY CONSIDERATIONS Wear goggles throughout this experiment.
At your lab bench, assemble a hot water bath using a 600 or 800 m L beaker and place the flask in the water bath as shown in Figure 1. After the water begins to boil, heat for an additional 15 minutes.
The reaction that is used for the synthesis is shown below.
In this reaction, an excess of acetic anhydride (C).
Record your observations and conclusions on the Data Sheet. Measure the melting point range of your synthesized aspirin with the Meltemp Apparatus as demonstrated by your lab instructor and compare to the value for pure aspirin of 138-140 A.
Weigh the aspirin and calculate the theoretical (maximum) yield.