Aldehydes and ketones (A-level only) common mistakes

Common mistakes

• Misidentifying functional groups

  Confusing aldehydes with ketones due to similar structures.

  Fix itRemember that aldehydes have a terminal carbonyl group, while ketones have a carbonyl group between two carbon atoms.

• Confusing aldehydes with ketones

  Students often think that both aldehydes and ketones will react with Tollens' reagent.

  Fix itRemember that only aldehydes can reduce Tollens' reagent; ketones do not react.

• Confusing aldehydes with ketones

  Students often confuse the oxidation reactions of aldehydes with those of ketones, which do not oxidize to carboxylic acids.

  Fix itRemember that only aldehydes can be oxidized to carboxylic acids, while ketones are resistant to oxidation.

• Confusing aldehydes with ketones

  Students often confuse the reactivity of aldehydes and ketones, thinking they react similarly.

  Fix itRemember that aldehydes are more reactive than ketones due to less steric hindrance around the carbonyl carbon.