Synthesis of Aspirin Lab

The video demonstrates how to make aspirin by combining salicylic acid (2.27g) and acetic anhydride (4-5mL). Sulfuric acid (5 drops) is added to create an acidic environment and speed up the reaction. The mixture is then heated in a boiling water bath for 10 minutes, resulting in a yellowish-brown tint.

After heating, 10mL of cold water is added, and the solution is placed in a cold water bath to allow aspirin crystals to form. The aspirin is then filtered from the solution using a sidearm flask, suction filter, and aspirator to create low pressure, aiding the filtration process. The filter paper, with the aspirin, is then rinsed with ethanol to dissolve the aspirin.

The dissolved aspirin in alcohol is recrystallized by adding 60mL of warm water, which initially makes the solution cloudy, indicating crystallization. The solution is stirred and then placed back into an ice water bath to allow larger, purer crystals to form.

A pre-weighed filter paper (0.354g) is used for the final filtration of the recrystallized aspirin. After filtration using the aspirator, the filter paper with the aspirin is placed on a watch glass to air dry. The final step involves weighing the dried filter paper and aspirin sample to determine the yield. A close-up of an aspirin crystal is shown.