Step (1): Generation of electrophile: by the action of Lewis acid FeCl₃ on Cl₂ to serve as a source of Cl⁺ (Electrophile) Step (2): Addition of electrophile to form carbocation: addition of electrophile to form C-Cl bond and form carbocation which is stabilized by resonance. Step (3): Loss of proton to re-form the aromatic ring by the action of FeCl₄⁻ which removes proton from carbon containing Cl and forming the aromatic ring again
