Question

Which one of the following undergoes reaction with 50% sodium hydroxide solution to give the corresponding alcohol and salt of acid ?

• A. Phenol
• B. Benzaldehyde
• C. Butanal
• D. Benzoic acid

Answer 1

The correct option is B Benzaldehyde

Generally, aldehydes with no 𝛼-H on treatment with strong base undergoes self oxidation and self reduction.
Benzaldehyde undergoes reaction with 50% sodium hydroxide solution to give benzyl alcohol and benzoic acid.
$PhCHO\stackrel{conc.NaOH}{\to }PhCO{O}^{-}N{a}^{+}+PhC{H}_{2}OH.$
This is an example of Cannizzaro Reaction which is a redox disproportionation reaction.