Question

Acetic acid can be halogenated in presence of phosphorus and chlorine. Formic acid cannot be halogenated with same way because of:

• A. presence of $\alpha -H$ atom in formic acid
• B. presence of $\alpha -H$ atom in acetic acid
• C. absence of $\alpha -H$ atom in $C{H}_{3}COOH$
• D. higher acidic strength of acetic acid than formic acid.

Answer 1

The correct option is B presence of $\alpha -H$ atom in acetic acid

HVZ reaction is given by only those carboxylic acids which have $\alpha -H$ atom. $C{H}_{3}COOH$ has three $\alpha -H$ atoms but formic acid does not have $\alpha$-hydrogen atom hence formic acid cannot be halogenated.