Give the reaction for the formation of $n$-butane from ethane.

$2CH_3-CH_3 + 2Br_2 \xrightarrow{hv} 2CH_3-CH_2Br + 2HBr$
$2CH_3-CH_2Br + 2Na \xrightarrow{\text{dry ether}} CH_3-CH_2-CH_2-CH_3 + 2NaBr$
Ethane $\rightarrow$ Bromination $\rightarrow$ Bromoethane $\rightarrow$ Wurtz reaction $\rightarrow$ $n$-Butane