Statement-I : Reactions of benzene diazonium chloride involving the replacement of -N₂Cl group are nucleophilic substitution.

Statement-II : $-{\mathrm{N}}_2^{+}$ ion is a good leaving group in nucleophilic substitution.

Due to the presence of positive charge on more electronegative nitrogen atom, $-{\mathrm{N}}_2^{+}$ group is a very good leaving group.

This make the benzene ring electron deficient which can be attached by nucleophiles like Cl^-, Br^-, CN^-, I^-, NO^-₂ , H^-, Ph^- .