The reagent used to convert acetyl chloride to acetaldehyde is –

Q.1 (x) The reagent used to convert acetyl chloride to acetaldehyde is –

A. SnCl₂ + HCl

B. Zn·Hg + Conc.HCl

C. NH₂NH₂, KOH / ethylene glycol (CH₂OH–CH₂OH)

D. H₂/Pd–BaSO₄

Doubtly Asked 28 Oct 2026 Board exam · June 2026 hsc 12th Save WhatsApp Report

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Answer: D. H2/Pd–BaSO4

Answer: (d) H₂/Pd–BaSO₄

This is the Rosenmund reduction. Pd supported on BaSO₄ (poisoned catalyst) reduces the acid chloride only up to the aldehyde stage:

CH₃COCl + H₂ \(\xrightarrow{\text{Pd}/\text{BaSO}_4}\) CH₃CHO + HCl

Zn–Hg/HCl and NH₂NH₂/KOH reduce C=O to CH₂; SnCl₂/HCl is used in Stephen reduction of nitriles.

Doubtly AI · 28 Oct 2026 AI-verified · Oct 2026 Report

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