Question

Write first five members of the homologous series of alkenes.

Answer 1

The general formula of alkenes is ${\text{C}}_n{\text{H}}_{2n}$.
With n=1 alkenes are not possible. So, the members of alkenes generally start from n=2.
$\bullet$The first member of the homologous series (n=2) is ${\text{C}}_2{\text{H}}_4$ (${\text{CH}}_2={\text{CH}}_2$).
$\bullet$The second member of the homologous series (n=3) is ${\text{C}}_3{\text{H}}_6$ (${\text{CH}}_3\text{CH}={\text{CH}}_2$).
$\bullet$The third member of the homologous series (n=4) is ${\text{C}}_4{\text{H}}_8$ (${\text{CH}}_3{\text{CH}}_2\text{CH}={\text{CH}}_2$).
$\bullet$The fourth member of the homologous series (n=5) is ${\text{C}}_5{\text{H}}_{10}$ (${\text{CH}}_3{\text{CH}}_2{\text{CH}}_2\text{CH}={\text{CH}}_2$).
$\bullet$The fifth member of the homologous series (n=6) is ${\text{C}}_6{\text{H}}_{12}$ (${\text{CH}}_3{\text{CH}}_2{\text{CH}}_2{\text{CH}}_2\text{CH}={\text{CH}}_2$).