Question

In homologous series of aldehyde, the consecutive members of the series differ by the mass of:

Answer 1

A homologous series may be defined as a group of a class of compounds, each member of which differs from the preceding or succeeding member by one $C{H}_2$. The members of the series are known as homologs.
Ethanal $\left(C{H}_{3}CHO\right)$ and propanal $\left(C{H}_{3}C{H}_{2}CHO\right)$ are two consecutive members of the homologous series of aldehydes. In these compounds, the physical properties such as melting point, boiling point, density, etc., gradually increase with the increase in the molecular weight.
The chemical properties of these compounds closely resemble due to the presence of the same functional group (aldehyde group) in them.