Choose the correct statement/statements for Cannizzaro reaction.
A. Takes place in aldehydes and ketones having absence of α-hydrogen
B. Takes place in aldehydes having absence of α-hydrogen
C. It is a disproportionation reaction
D. Get a mixture of carboxylic acid salt and ethers
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → B, C only
In the Cannizzaro reaction, an aldehyde with no α-hydrogen is heated with concentrated alkali; one molecule is reduced to an alcohol and another is oxidised to the salt of a carboxylic acid, so the reaction is a disproportionation:
\( \ce{2HCHO + KOH} \xrightarrow[\Delta]{\text{conc.}} \ce{CH3OH + HCOOK} \)
(A) Takes place in aldehydes and ketones having absence of α-hydrogen — False. Ketones do not undergo the Cannizzaro reaction; it is a reaction of aldehydes only.
(B) Takes place in aldehydes having absence of α-hydrogen — True. Examples are HCHO and \( \ce{C6H5CHO} \).
(C) It is a disproportionation reaction — True. The same aldehyde is both oxidised and reduced.
(D) Get a mixture of carboxylic acid salt and ethers — False. The products are a carboxylic acid salt and an alcohol, not an ether.
NCERT (2026-27 edition):
Other Reactions
