Question

what happens when methane reacts with chlorine

Answer 1

when methane reacts with chlorine it undergoes substitution reaction....
reactions are:
CH4  +  Cl2-->CH3Cl  +  HCl
CH3Cl  +  Cl2-->CH2Cl2  +  HCl
CH2Cl2  +  Cl2-->CHCl3  +  HCl
CHCl3  +  Cl2-->CCl4  +  HCl

Answer 2

Answer: A mixture of haloalkanes are formed when methane is reacted tith chlorine gas.

Explanation:

Methane is an alkane having formula $CH_4$, when it is reacted with chlorine gas, at first it will produce chloromethane by a process of photohalogentaion because it occurs in the presence of sunlight.

A number of substitution reactions occur in which hydrogen atoms in the methane are replaced one at a time by chlorine atoms. the products obtained will be a mixture of chloromethane, dichloromethane, trichloromethane and tetrachloromethane.

The reactions of this are as follows:

$CH_4+Cl_2\rightarrow CH_3Cl+HCl\\\\CH_3Cl+Cl_2\rightarrow CH_2Cl_2+HCl\\\\CH_2Cl_2+Cl_2\rightarrow CHCl_3+HCl\\\\CHCl_3+Cl_2\rightarrow CCl_4+HCl$