Question

Aryl halide is less reactive than alkyl halide towards nucleophilic substitution because:

• A. of less stable carbonium ion
• B. due to large $C-Cl$ bond energy
• C. of inductive effect
• D. of resonance stabilization and $s{p}^2$ hybridization of $C$ attached to halide

Answer 1

The correct option is D of resonance stabilization and $s{p}^2$ hybridization of $C$ attached to halide

Aryl halide is less reactive than alkyl halide towards nucleophilic substitution because of the resonance stabilization and $s{p}^2$ hybridization of $C$ attached to halide. Due to resonance, carbon-chlorine bond acquires partial double bond character, hence it becomes shorter and stronger, and thus, cannot be easily replaced by nucleophiles. This effect is further enhanced by the $s{p}^2$ nature of the $C$ atom to which chlorine is attached.