Question

Butane to Ethane Organic conversion

Answer 1

first convert methane to ethane---
CH4 + Cl2 ---------> CH3Cl (in presence of light)
CH3Cl + Na/ether --------> CH3-CH3 (ethane) (wurtz reaction)

now convert ethane to butane----
CH3-CH3 + Br2 --------> CH3-CH2-Br (in presence of light)
CH3-CH2-Br + Na/ether --------> CH3CH2-CH2CH3 (butane) (wurtz reaction)