Halogenation of Methane: Global Reaction
The halogenation of methane is a reaction that proceeds with the formation of free radicals and takes place in three stages.
Initiation Stage
In the first step of the reaction, the homolytic cleavage of the Cl-Cl bond occurs. This is achieved with heat or by absorbing light.
First Propagation Stage
This is a slightly endothermic stage that involves the abstraction of a hydrogen atom from methane by the chlorine radical formed in the previous stage, generating the methyl radical.
Second Propagation Stage
During this stage, the methyl radical abstracts a chlorine atom from one of the initial molecules, producing chloromethane and a new chlorine atom. This chlorine atom returns to the first propagation stage, and the whole process repeats.
Termination Stage
This occurs when the reactants are exhausted, and the radicals in the medium combine with each other.
