The molecular formula of a homologue of butane is

Homologue series of alkanes as follows

$(GF:C_n{H}_{2n+2},n=1,2,3,\mathrm{4......}etc)$

${\text{CH}}_{\text{4}}-\text{\hspace{0.17em}Methane}$

${\text{C}}_2{\text{H}}_6-\text{Ethane}$

${\text{C}}_{\text{3}}{\text{H}}_8-\text{propane}$

${\text{C}}_{\text{4}}{\text{H}}_{\text{10}}-\text{Butane}$

${\text{C}}_{\text{5}}{\text{H}}_{\text{12}}-\text{Pentane}$