Homologous Series Characteristics:
General formula: All the members of a series can be represented by same general formula.
Same functional group: All members of a series contain the same functional group i. e. alcohol has -OH group and amine has –NH2 grou p etc.
Difference in molecular mass of two consecutive members of the series is 14 unit i.e. CH2.
Preparative method: All the members of the series can be prepared by common methods, only in special cases different methods may be used.
Identical chemical properties: Similar types of chemical properties are observed due to same functional group. However with increasing molar mass the chemical reactivity deceases to some extent.
Regular order in physical property: With increase in molar mass, there is a gradual change in physical properties. For example, boiling and inciting temperatures increase with molar mass- increment but solubility decreases.