Question

If $\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$ is the first member of the homologous series of alkenes, write the molecular formuale of the next three members of this series.

Answer 1

Homologous series of compound lies in the same family and the molecular formula is different by one $\left({\mathrm{CH}}_2\right)$ unit.

Alkenes contains double bond between the Carbon atoms so, it is an unsaturated hydrocarbon.

The general formula of alkenes is $\left({\mathrm{C}}_{\mathrm{n}}{\mathrm{H}}_{2\mathrm{n}}\right)$.

The first member of the homologous series of alkenes is Ethene having the formula $\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$.

The formulae of the next three members of the homologous series of alkenes are Propene $\left({\mathrm{C}}_3{\mathrm{H}}_6\right)$, Butene $\left({\mathrm{C}}_4{\mathrm{H}}_8\right)$, and Pentene$\left({\mathrm{C}}_5{\mathrm{H}}_{10}\right)$.

All the three homologue of alkenes Propene $\left({\mathrm{C}}_3{\mathrm{H}}_6\right)$, Butene $\left({\mathrm{C}}_4{\mathrm{H}}_8\right)$, and Pentene $\left({\mathrm{C}}_5{\mathrm{H}}_{10}\right)$ are differed by $\left({\mathrm{CH}}_2\right)$ and mass number$14$.