C2H5Br (Ethyl bromide) undergoes an elimination reaction to form C2H4 (Ethylene) and HBr: C2H5Br -> C2H4 + HBr
C2H4 (Ethylene) can then undergo a substitution reaction with Cl2 (Chlorine) to form C2H4Cl (Chloroethene) by replacing one of the hydrogen atoms with a chlorine atom: C2H4 + Cl2 -> C2H4Cl
The reaction steps are as follows:
C2H5Br (Ethyl bromide) undergoes an elimination reaction to form C2H4 (Ethylene) and HBr:
C2H5Br -> C2H4 + HBr
C2H4 (Ethylene) can then undergo a substitution reaction with Cl2 (Chlorine) to form C2H4Cl (Chloroethene) by replacing one of the hydrogen atoms with a chlorine atom:
C2H4 + Cl2 -> C2H4Cl