MHTCET 18 Apr 2026 Shift 2 Paper

Concept:Nitriles hydrolyse to amides first, then to carboxylic acids with further hydrolysis.Explanation:Ethyl cyanide is $\mathrm{C}_{2}\mathrm{H}_{5}\mathrm{CN}$. When it reacts with $\mathrm{H}_{2}\mathrm{O}$, the nitrile group is partially hydrolysed to form an amide.$$\mathrm{C}_{2}\mathrm{H}_{5}\mathrm{CN} \xrightarrow{\mathrm{H}_{2}\mathrm{O}} \mathrm{C}_{2}\mathrm{H}_{5}\mathrm{CONH}_{2}$$So $A$ is propanamide ($\mathrm{C}_{2}\mathrm{H}_{5}\mathrm{CONH}_{2}$).On further hydrolysis with water and dilute $\mathrm{HCl}$, the amide is completely hydrolysed to a carboxylic acid:$$\mathrm{C}_{2}\mathrm{H}_{5}\mathrm{CONH}_{2} \xrightarrow{\mathrm{H}_{2}\mathrm{O} / \text{dil } \mathrm{HCl}} \mathrm{C}_{2}\mathrm{H}_{5}\mathrm{COOH} + \mathrm{NH}_{3}$$Thus $B$ is $\mathrm{C}_{2}\mathrm{H}_{5}\mathrm{COOH}$, which is propanoic acid.Answer:C. Propanoic acid