Halogenation of alkanes will lead to the formation of alkyl halide. In this reaction, if we use Cl₂ in excess, then dichloro and trichloro forms as product and if ethane is used in excess, ethyl chloride forms as major product. So, the reaction takes place as follows:

C₂H₆+Cl₂→C₂H₅Cl+HCl 
(excess)