Question

Write the name and formula of the 2nd member of homologous series having general formula CnH2n.

Answer 1

2nd Member of Homologous Series having $\textbf{\red{General Formula Cn H2n}}$ would be Propene and not Ethene.
Because in Alkenes there is a double bond of C=C
And as we all know that Single Carbon (meth) has only one Carbon so it can't form double bond.
So the $\textbf{\green{1st Member of Homologous Series}}$ would automatically be ${\green{Ethene}}$ &$\textbf{\blue {2nd Member of Homologous Series}}$ would Hence be $\blue{Propene}$.

Hope it helps you :)

#${\red{\underline{Be Brainly}}}$

Answer 2

Alkenes have the General formula CnH2n

So in Alkenes the 2nd member would be Propene