Question

Out of formic acid and acetic acid, which one will give the HVZ reaction? Give a suitable reason in support of your answer and write the chemical reaction involved.

Answer 1

Acetic acid will give HVZ reaction.
Carboxylic acids having an α-hydrogen are halogenated at the α-position on treatment with chlorine or bromine in the presence of a small amount of red phosphorus to give α-halo carboxylic acids.

\[\ce{CH3COOH ->[Br2/red P] CH2BrCOOH}\]