Nitrile hydrolysis yields carboxylic acids

Steps:

• Compound W (C, H, N) reacts with HCl(aq) to form propanoic acid (CH₃CH₂COOH), indicating acid hydrolysis.
• Amines react with HCl to form ammonium salts, not carboxylic acids.
• Nitriles (R-CN) hydrolyze under acidic conditions to carboxylic acids (R-COOH) with the same carbon chain length.
• Propanoic acid has three carbons, so W is propanenitrile (CH₃CH₂CN).

Why D is correct:

• Propanenitrile hydrolyzes with HCl to propanoic acid, as the nitrile group (-CN) adds a carboxyl group (-COOH) via R-CN + 2H₂O + HCl → R-COOH + NH₄Cl.

Why the others are wrong:

• A: Ethylamine (CH₃CH₂NH₂) forms ethylammonium chloride with HCl, not propanoic acid.
• B: Ethanenitrile (CH₃CN) hydrolyzes to ethanoic acid (CH₃COOH), not propanoic acid.
• C: Propylamine (CH₃CH₂CH₂NH₂) forms propylammonium chloride with HCl, not propanoic acid.

Final answer: D