An unknown compound $X$ on chlorination followed by Wurtz reaction and dehydrohalogenation gives ethene. Provide the complete reaction sequence in a stepwise manner.

(N/A) The conversion of methane $(CH_4)$ to ethene $(CH_2=CH_2)$ proceeds through the following steps:
$Step \ 1: CH_4 + Cl_2 \xrightarrow{h\nu} CH_3Cl + HCl$ (Chlorination)
$Step \ 2: 2CH_3Cl + 2Na \xrightarrow{dry \ ether} CH_3-CH_3 + 2NaCl$ (Wurtz reaction)
$Step \ 3: CH_3-CH_3 + Cl_2 \xrightarrow{h\nu} CH_3-CH_2Cl + HCl$ (Chlorination)
$Step \ 4: CH_3-CH_2Cl + alc.KOH \rightarrow CH_2=CH_2 + KCl + H_2O$ (Dehydrohalogenation)
Thus,the unknown compound $X$ is methane $(CH_4)$.