Which electrophilic aromatic substitution reaction is reversible? A. Nitration B. Alkylation C. Alkanoylation D. Sulfonation E. Halogenation

D. Sulfonation

Explanation:

Electrophilic aromatic substitution -

The subsitution reaction, where the hydrogen atom of an aromatic ring is replaced by an external electrophile.

Sulfonation reaction -

The subsitution reaction, where the hydrogen atom of an aromatic ring (benzene) is replaced by an sulfonyl group, is called an Sulfonation reaction.

The Sulfonation reaction is reversible in nature, because, heating of aqueous sulfuric acid with sulfonic acid, can lead to a reverse reaction, i. e., desulfonation.