Glossary - Aldehydes and Ketones - for IIT JEE

Aldehydes
Aldehydes contain carbonyl group C=O as functional group and the carbonyl atom carries at least one H atom.

Cannizzaro reaction
Aldehydes which do not have α-hydrogen atom react with concentrated sodium hydroxide (NaOH) or potassium hydroxide (KOH) in such a way that one molecule get oxidized to acid and the second molecule gets reduced to alcohol.

Note two molecules of aldehyde participates in the reaction.

This self oxidation-reduction under the influence of a base is known as the Cannizzaro's reaction.




Ketones

In ketones, also carbonyl group C=O is the functional group. But the carbonyl carbon does not contain any H atoms, but it is attached to two alkyl or aryl groups.

Cannizzaro reaction
Aldehydes which do not have α-hydrogen atom react with concentrated sodium hydroxide (NaOH) or potassium hydroxide (KOH) in such a way that one molecule get oxidized to acid and the second molecule gets reduced to alcohol.

Note two molecules of aldehyde participates in the reaction.

This self oxidation-reduction under the influence of a base is known as the Cannizzaro's reaction.