Question

Why addition of hcn to aldehyde or ketone is catalysed by a base?

Answer 1

Answer:

The reaction of aldehydes and ketones with hydrogen cyanide

Explanation:

Hydrogen cyanide adds across the carbon-oxygen double bond in aldehydes and ketones to produce compounds known as hydroxynitriles. ... The pH of the solution is adjusted to about 4 - 5, because this gives the fastest reaction.

Answer 2

Answer:

Aldehydes and ketones undergo reaction with HCN to produce cyanohydrins. ... Hence, base as a catalyst helps to speed up the reaction. This is because catalysis helps in the generation of cyanide ion (CN) which acts as a stronger nucleophile and adds to carbonyl compounds to produce the corresponding cyanohydrin.