if you find salicylic acid or acetic anhydride in your aspirin synthesis product why are they there? Where did they come from?

Probably they came from the stock room or wherever chemicals are stored at your facility. Both are starting materials for the synthesis of aspirin.

If you find salicylic acid or acetic anhydride in your aspirin synthesis product, it means that the synthesis process did not go as planned or that some impurities were introduced during the reaction. Both salicylic acid and acetic anhydride can be involved in the synthesis of aspirin, but they should not be present in the final product if the reaction proceeds correctly.

Salicylic acid is the starting material in the synthesis of aspirin. It is commonly obtained from natural sources such as willow bark or synthesized chemically. In the aspirin synthesis process, salicylic acid is reacted with acetic anhydride to produce aspirin and acetic acid as a byproduct.

Acetic anhydride serves as an acetylating agent, meaning it provides the acetyl group necessary for the chemical reaction to convert salicylic acid into aspirin. Acetic anhydride is also used in excess quantities to ensure the complete reaction and maximize the yield of aspirin.

If either salicylic acid or acetic anhydride is found in the aspirin synthesis product, it suggests that the reaction did not fully proceed or some impurities were introduced. Possible reasons for this could include incomplete reaction, insufficient reaction time or temperature, incorrect stoichiometry of reagents, or impurities present in the starting materials.

To prevent the presence of salicylic acid or acetic anhydride in the final product, it is important to follow proper laboratory techniques including precise measurement of reagents, ensuring optimal reaction conditions, and allowing sufficient reaction time for the conversion to occur. Additionally, purification steps such as filtration or recrystallization can be employed to separate the final product from any unwanted impurities.