Explain the isomerization reaction of alkanes.

(N/A) $n$-Alkanes,upon heating in the presence of anhydrous aluminium chloride $(AlCl_3)$ and hydrogen chloride $(HCl)$ gas,undergo isomerization to form branched-chain alkanes.
For example,$n$-hexane isomerizes to a mixture of $2$-methylpentane and $3$-methylpentane as shown below:
$CH_3(CH_2)_4CH_3 \xrightarrow[HCl_{(g)}]{Anhy. AlCl_3} CH_3CH_2CH(CH_3)CH_2CH_3 + CH_3CH(CH_3)CH_2CH_2CH_3$
($n$-Hexane) $\rightarrow$ ($3$-methylpentane) + ($2$-methylpentane)