Question

Why is the α-hydrogens of aldehydes and ketones are acidic in nature?

Account for the following:

The alpha (α)-hydrogens of aldehydes and ketones are acidic in nature.

Answer 1

Because of the strong electron-withdrawing nature of the carbonyl groups and the resonance stabilisation of the conjugate base, aldehydes and ketones are acidic in nature.

\[\begin{array}{cc} \ce{R}\phantom{..........}\\ \backslash\phantom{........}\\ \ce{C = O}\\ /\phantom{........}\\ \ce{H}\phantom{..........}\\ \end{array}\]	\[\begin{array}{cc} \ce{R}\phantom{..........}\\ \backslash\phantom{........}\\ \ce{C = O}\\ /\phantom{........}\\ \ce{R}\phantom{..........}\\ \end{array}\]
Aldehyde	Ketone