Question

What is homologous series of carbon compounds? Write the molecular formula of two consecutive members of homologous series of aldehydes .
State which part of these compounds determines their:
I) physical and II) chemical properties

Answer 1

A series of organic compounds which differ by a ch2 group is called homologous series.

Methanal,ethanal are the first two members of aldehyde group

Answer 2

The physical property of any particular member of a homologous series depends on its size, or its position within the homologous series. The physical properties, such as solubility, melting point, boiling point, specific gravity etc. show a gradual change with the increase in their relative molecular masses.