Chemistry Aldehydes, Ketones and Carboxylic Acids 2 Marks
Appeared in: 2026 (2 sets)
Organic compounds containing carbonyl group as the functional group are aldehydes, ketones and carboxylic acids. The carbon-oxygen double bond is polarised due to higher electronegativity of oxygen as compared to carbon. Aldehydes are generally more reactive than ketones in nucleophilic addition reactions due to steric and electronic reasons. They react with $\text{HCN}$, Sodium bisulphite, Grignard reagent and a number of ammonia derivatives like Hydroxylamine, Hydrazine, Semicarbazide, etc. Aldehydes and ketones undergo various reactions due to the acidic nature of $\alpha$-hydrogen. Aldehydes and ketones having at least one $\alpha$-hydrogen atom undergo a reaction in the presence of dilute alkali as a catalyst to form $\beta$-hydroxy aldehydes or $\beta$-hydroxy ketones. On the other hand, aldehydes which do not possess an $\alpha$-hydrogen undergo self-oxidation and reduction in the presence of concentrated alkali. (a) From the compounds given below, identify which would undergo aldol condensation and which would undergo Cannizzaro reaction ? Cyclohexanone, Benzaldehyde, Methanal, 2-Methylpentanal