Here are some additional questions relating to aspirin synthesis:
- Can you explain what happened to the -OH group in the salicylic acid when the acetic acid was added? The -OH group from the salicylic acid combined with the acetic acid, producing water and an ester group. Can you see what effect this had on the end product? This reduced the strength of the acid and made the aspirin easier to ingest.
- Why do you think the aspirin was washed with distilled water? How did this affect the end product? How did this affect the actual product yield? Washing the aspirin removed most of the unreacted salicylic acid and acetic anhydride to yield a purer product. Some product was dissolved and lost in the washing process. Cold water was used to miminize dissolving the product.
- How did the synthesis use different temperatures to affect solubility of aspirin? At higher temperatures (warm water), molecules have more kinetic energy and collide with each other more often to interact with water molecules, increasing the solubility of the aspirin. The ice bath slowed the molecules, allowing them to more easily stick together and "fall out" of solution or crystallize.
