The mechanism of electrophilic substitution in chlorobenzene is similar to that of benzene, but with some differences due to the presence of the chlorine atom. The general mechanism for electrophilic substitution in aromatic compounds involves three steps: electrophile generation, electrophilic attack, and deprotonation.1. Electrophile generation: In this step, a strong Lewis acid such as AlCl3 or FeCl3 reacts with a halogen molecule like Cl2 or Br2 to form a highly reactive electrophile. For example, in the case of chlorination, the reaction is as follows:Cl2 + AlCl3 [Cl- AlCl4] + Cl+2. Electrophilic attack: The electrophile Cl+ in this case attacks the aromatic ring, forming a resonance-stabilized carbocation intermediate called a sigma complex or arenium ion. The chlorine atom in chlorobenzene has a lone pair of electrons, which can participate in resonance with the aromatic ring. This results in the electron density being distributed differently compared to benzene. The chlorine atom is an electron-withdrawing group EWG through the inductive effect, but it is also an electron-donating group EDG through resonance also known as the mesomeric effect . The overall effect of the chlorine atom on the reactivity of chlorobenzene is a combination of these two opposing effects.3. Deprotonation: A base, usually the halide ion Cl- in this case , abstracts a proton from the carbocation intermediate, restoring the aromaticity of the ring and generating the substituted product.The main difference between the electrophilic substitution mechanisms of chlorobenzene and benzene lies in the electronic effects of the chlorine atom on the aromatic ring. In chlorobenzene, the chlorine atom influences the reactivity and the regioselectivity of the electrophilic substitution. Due to the combined inductive and mesomeric effects, chlorobenzene is less reactive than benzene towards electrophilic substitution reactions. Additionally, the chlorine atom directs the incoming electrophile to the ortho and para positions, making these positions more reactive than the meta position. This is because the resonance effect of the chlorine atom stabilizes the positive charge at the ortho and para positions in the sigma complex intermediate.