Explain the mechanism of chlorination of methane?

Chlorination of methane is a chain reaction that occurs in the presence of ultraviolet (UV) light or heat. It produces chlorinated hydrocarbons like methyl chloride, methylene chloride, chloroform, and carbon tetrachloride.

The mechanism involves three main steps:

1. Initiation: UV light breaks chlorine molecules (Cl₂) into free radicals: Cl₂ → 2Cl•.

2. Propagation:

   • Cl• + CH₄ → CH₃• + HCl
   • CH₃• + Cl₂ → CH₃Cl + Cl•

   This continues as a chain reaction.

3. Termination: Free radicals combine to stop the chain: Cl• + Cl• → Cl₂, CH₃• + Cl• → CH₃Cl.

This mechanism demonstrates the importance of free radicals and the role of light in halogenation reactions.