Subsritution reaction has three strps –
In the reaction shown above, bromine is initiated under UV rays forming Bromine radicals.
There are two steps in propagation;
-Firstly, Ethane reacts with Bromine radical. A single C-H bond is broken by homolytic fission, forming a ethyl radical and HBr.
-Secondly, the ethyl radical reacts with a bromine molecule. The organic product, bromoethane is formed together with a further Bromine radical.
In termination stage, two radicals combine together to form a molecule, and there are three possibilities as shown above.