Explain the mechanism of halogenation or chlorination of benzene.

Explanation

Halogenation: Benzene reacts with chlorine in the presence of `FeCl_(3)` or `AlCl_(3)` to form chlorobenzene.

Mechanism: This involves the following steps.
Step 1: Generation of electrohile `Cl+Cl-Cl+FeCl_(3)toCl^(+)+FeCl_(4)^(-)`
Step 2: The electrophile `Cl+` attacts benzene ring a carbon which is resonance stabilised.

Step 3: Loss of a proton to give chlorobenzene. The proton is removed by `FeCl_(4)`