Question

Number of compounds which are more reactive than towards electrophilic substitution reaction

Answer 1

When electron-withdrawing groups such as $–N{O}_2,–CHO,–Cl$​ are present on the benzene ring, they decrease the electron density of the benzene ring and deactivate it towards electrophilic aromatic substitution reaction.

When electron releasing groups such as $-O^{-}$ , $-N{H}_2$​ are present, they increase the electron density on benzene ring and activate the ring towards electrophilic aromatic substitution reaction and only $-O^{-}$ and $-N{H}_2$ groups having more electron-donating tendency than $–OH$ group on benzene.