MHTCET 16 May 2024 Shift 2 Paper

Concept:Acidic hydrolysis of nitriles converts a cyano group ($-\mathrm{CN}$) into a carboxylic acid group ($-\mathrm{COOH}$) without changing the carbon skeleton.Explanation:The given reaction involves a nitrile, $\mathrm{C}_6\mathrm{H}_5-\mathrm{CH}_2-\mathrm{CN}$, treated with water in the presence of an acid.During hydrolysis, the $-\mathrm{CN}$ group is transformed into $-\mathrm{COOH}$.The phenyl group ($\mathrm{C}_6\mathrm{H}_5-$) and the methylene group ($-\mathrm{CH}_2-$) remain attached to the carboxyl carbon.Thus, the product formed is $\mathrm{C}_6\mathrm{H}_5-\mathrm{CH}_2-\mathrm{COOH}$, which is phenylacetic acid.No extra carbon atoms are added, so option B is not formed.The $-\mathrm{CH}_2-$ group is not lost, so benzoic acid (option D) is not produced.Phenol (option C) would require removal of the entire side chain, which does not occur here.Therefore, the correct product is phenylacetic acid.Answer:Option A: $\mathrm{C}_6\mathrm{H}_5-\mathrm{CH}_2-\mathrm{COOH}$ (Phenylacetic acid).