Question

Assertion (A) : Chlorobenzene is less reactive towards nucleophilic substitution reaction.

Reason (R) : Nitro group in chlorobenzene increases its reactivity towards nucleophilic substitution reaction.

(A) Both A and R are true and R is the correct explanation of A.

(B) Both A and R are true and R is not the correct explanation of A.

(C) A is true but R is false.

(D) A is false but R is true.

Answer 1

Option : (B) Both A and R are true and R is not the correct explanation of A.

Chlorobenzene is less reactive towards nucleophilic substitution reaction due to the delocalization of the electrons of C-Cl bond and a partial double bond character develop in the bond which make it difficult for nucleophile to cleave C-Cl bond.

When Nitro group present at ortho and para position it withdraw electrons from benzene ring and helps to attack of Nucleophiles on haloarene. that's why. Nucleophilic Substitution increases.