See image — Aldehydes Ketones and Carboxylic Acids Chemistry Question

💡 Solution & Explanation

Step 1: Identify the reaction sequence concept. We start with an alkyl halide (ethyl chloride, CH3CH2Cl) and perform three successive reactions. Step 2: First reaction - CH3CH2Cl + NaCN → (i). NaCN is a nucleophile that displaces the chloride via SN2 reaction, introducing a nitrile group. Product (i) = CH3CH2CN (propionitrile). Step 3: Second reaction - CH3CH2CN + Ni/H2 → (ii). Catalytic hydrogenation (reduction) of a nitrile group converts -CN to -CH2NH2. Product (ii) = CH3CH2CH2NH2 (propylamine, a primary amine). Note: the nitrile carbon gains two hydrogens and the nitrogen gains two hydrogens, extending the carbon chain by one carbon. Step 4: Third reaction - CH3CH2CH2NH2 + acetic anhydride → (iii). Acetic anhydride reacts with primary amines to form amides (acetylation of the amine). The -NH2 group reacts with (CH3CO)2O to give -NHCOCH3 and release CH3COOH. Product (iii) = CH3CH2CH2NHCOCH3 (N-propylacetamide). Step 5: Match with options. Option (c) CH3CH2CH2NHCOCH3 matches exactly. Why other options fail: - (a) CH3CH2CH2NH2 is intermediate (ii), not the final product after acetylation. - (b) CH3CH2CH2CONHCH3 would require a different reaction pathway involving amide bond formation with methylamine, not acetic anhydride acting on the amine. - (d) CH3CH2CH2CONHCOCH3 is not produced by acetylation of a primary amine with acetic anhydride under normal conditions. Therefore, the correct answer is C.