Question

Why does p- nitrochlorobenzene undergo nucleophilic substitution faster than chlorobenzene ?

Answer 1

Bcoz inductive effect produce by the nitro group at pera position and decrease the election density at benzene ring so nucleophile easily attack on benzene ring

Answer 2

In chlorobenzene, the -ve charge is delocalized within the ring. In the case of p-Nitrochlorobenzene, the presence of strong electron withdrawing group like Nitro additional delocalizes the charge as a result of it comes on the negative O atom. We all know that more is that the delocalization, more is that the resonance, the stable is that the intermediate product shaped and thus more is that the speed of reaction.