Question

What is a homologous series and what are its characteristics? [5 MARKS]

Answer 1

Homologous series: 1 Mark
Characteristics: 4 Marks

The series of organic compounds having same general formula, same functional group and similar chemical properties is called homologous series. Each member of the series is called a homologue.

The compounds belonging to the homologous series have the following characteristics:
(a) Each member of the series can be represented by the same general formula.
(b) All members of the series can be prepared by the same general methods of preparation.
(c) The members of the series show similar chemical properties.
(d) The first member of each series sometimes shows an unusual behaviour.
(e) The physical properties such as solubility, melting point, boiling point, specific gravity, etc., show a gradual increase with the increase in the molecular weight.