Hydrocarbons Part 1

Rate of nucleophilic substitution in aromatic halide are as follows Greater the number of nitro (−NO2) group in chlorobenzene,
greater the rate of nucleophilic substitution reaction in aromatic halides.
When a nitro group is present at orthoand para position, it can withdraw electrons from the benzene ring. This facilitates, the attack of nucleophiles on haloarenes.