CBSE 2025 · Region 6 · Set 1 · Q27 · 3 marks

A compound (A) with molecular formula $\displaystyle \mathrm{C}_{4} \mathrm{H}_{5} \mathrm{~N}$ on reduction with DIBAL-H followed by hydrolysis, gives a compound (B). Compound (B) gives positive Tollens' test but does not give iodoform test. Compound (B) can also be obtained when ethanal is treated with dilute NaOH followed by heating. Identify (A) and (B). Write the reactions of (A) with DIBAL-H followed by hydrolysis.

CBSE Class 12 Chemistry past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.