Characteristics of homologous series

(i) All the members of a series can be presented by the general formula. For instance, the members of the alcohol family are illustrated by the formula CnH₂n⁺¹OH in which n may have numbers 1, 2, 3, 4.... So on.

(ii) Two successive members are different in their formula by -CH₂ group or by 14 atomic mass units (12+2*1).

(iii) Different types of members in a family have common functional group for example, the members of the alcohol family comprise -OH group as the functional group.

(iv) The members in any specific family have almost similar chemical properties and their physical properties like boiling point, and melting point, solubility, density etc., display a proper gradation with the raise in the molecular mass.

(v) The members exist in a specific series can be prepared approximately by similar methods termed as the general methods of preparation.