Answer and Explanation:
When methane (CH4) and chlorine (Cl2) react, a substitution reaction takes place. Specifically, the reaction is a halogenation reaction, in which one or more hydrogen atoms in the methane molecule are replaced by chlorine atoms. The reaction can be represented by the following equation:
CH4 + Cl2 → CH3Cl + HCl
In this equation, CH3Cl represents chloromethane, which is a type of organochlorine compound. The reaction is typically initiated by ultraviolet (UV) light or heat, and it proceeds through a series of free radical chain reactions. The products of the reaction are typically a mixture of chloromethane and hydrogen chloride (HCl) gas.