Question

What is the relation between ${\mathrm{C}}_2{\mathrm{H}}_4$ and ${\mathrm{C}}_3{\mathrm{H}}_6$?

Answer 1

Step 1: Introduction

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

If a compound adds or subtracts by one unit of ${\mathrm{CH}}_2$ from that compound then it is a homologous compound.

Step 2: Relation between ${\mathrm{C}}_2{\mathrm{H}}_4$ and ${\mathrm{C}}_3{\mathrm{H}}_6$

The next homologous of ${\mathrm{C}}_2{\mathrm{H}}_4$ compound is by adding one unit of ${\mathrm{CH}}_2$

$$\begin{gathered} {\mathrm{C}}_2{\mathrm{H}}_4+{\mathrm{CH}}_2\to {\mathrm{C}}_3{\mathrm{H}}_6 \\ (\mathrm{lower}\mathrm{homologue})(\mathrm{higher}\mathrm{homologue}) \end{gathered}$$

Hence, these two compounds are Homologues to each other.