The number of carbon atoms present in the molecule of the fifth number of the homologous series of alkynes is

The homologous series of the alkyne is as follows                                            $$ 

${\text{General Formula for alkynes:C}}_{\text{n}}{\text{H}}_{2n-2},n=2,3,4\dots \text{etc}$

${\text{C}}_{\text{2}}{\text{H}}_{\text{2}}\to \text{Ethyne}$

${\text{C}}_{\text{3}}{\text{H}}_{\text{4}}\to \text{Propyne}$

${\text{C}}_{\text{4}}{\text{H}}_{\text{6}}\to \text{Butyne}$

${\text{C}}_{\text{5}}{\text{H}}_{\text{8}}\to \text{Pentyne}$

${\text{C}}_{\text{6}}{\text{H}}_{\text{10}}\to \text{Hexyne}$