Alkyl halide to carboxylic acid via nitrile intermediate

Steps:

• 1-Bromopropane (CH₃CH₂CH₂Br) reacts with CN⁻ in SN2 substitution to form propanenitrile (CH₃CH₂CH₂CN).
• Propanenitrile undergoes hydrolysis under acidic or basic conditions.
• Hydrolysis converts the nitrile to an amide intermediate (CH₃CH₂CH₂CONH₂).
• Further oxidation/hydrolysis yields propanoic acid (CH₃CH₂COOH).

Why A is correct:

• Propanenitrile hydrolysis directly produces propanoic acid, extending the carbon chain by one and matching the oxidation step.

Why the others are wrong:

• B: Propanone requires ketone formation, not from substitution-oxidation of primary alkyl halide.
• C: Propylamine forms via substitution with NH₃, but no oxidation involved.
• D: Propyl ethanoate is an ester, needing alcohol formation and esterification, not direct oxidation.

Final answer: A