Write the reaction equation for the conversion of ethane to butane.

Let’s write down the chain of transformations for alkanes:
C2H6 – C2H5Cl – C4H10;
Let’s implement the solution:
C2H6 + Cl2 = C2H5Cl + HCl – substitution reaction, possible in the light, obtained chloroethane;
2С2Н5Cl + 2Na = C4H10 + 2NaCl – Wurtz reaction, occurs when heated, serves to lengthen the carbon chain, butane is formed.
These reactions show the formation of halogenated hydrocarbons. The reaction products find practical applications, for example, ethane chloride is used as a solvent, and butane in natural gas is used as a fuel.