Question

Which functional group is found in salicylic acid but not in aspirin?

1) Hydroxyl group
2) Carboxyl group
3) Ester group
4) Amine group

Answer 1

The hydroxyl group is found in salicylic acid but not in aspirin, as it is replaced by an ester group in aspirin.

Step-by-step explanation:

The functional group found in salicylic acid but not in aspirin is the hydroxyl group. Salicylic acid, also known as 2-hydroxybenzoic acid, contains both a carboxyl group (-CO₂H) and a hydroxyl group (-OH) attached to the aromatic ring. In contrast, aspirin, or acetylsalicylic acid, has an ester group in place of the hydroxyl group due to the esterification of the phenolic hydroxyl group with acetic anhydride during the synthesis of aspirin. Consequently, the aspirin molecule contains an ester group (-COOCH₃) rather than a free hydroxyl group.