Aldehydes, Ketones and Carboxylic Acids — Important Questions

Oxidation of primary alcohols, Rosenmund reduction of acyl chlorides, Stephen reaction from nitriles

Aldehydes can be prepared by oxidation of primary alcohols, Rosenmund reduction of acyl chlorides, and Stephen reaction from nitriles. Oxidation of secondary alcohols gives ketones, and Friedel-Crafts acylation is used to prepare ketones.

True

True. Fehling's test is used to distinguish between aldehydes and ketones. Aldehydes give a positive test (reddish brown precipitate of Cu₂O), while ketones do not react with Fehling's reagent under normal conditions.

Addition of HCN, Addition of NaHSO₃, Addition of alcohols, Addition of Grignard reagents

Nucleophilic addition reactions to carbonyl compounds include addition of HCN, NaHSO₃, alcohols, and Grignard reagents. Halogenation is not a nucleophilic addition but an electrophilic substitution reaction.

True

True. Aldehydes are more reactive than ketones due to both steric and electronic factors. Sterically, aldehydes have less hindrance around the carbonyl carbon. Electronically, the single alkyl group in aldehydes provides less electron density to the carbonyl carbon compared to two alkyl groups in ketones.