Each member of the series is called homologue.
Characteristics of homologous series
- All homologues of a series have the same general formula e.g., all alkanes have the general formula CnH2n+2.
- Each consecutive member differs from the next by one carbon atom and two hydrogen atoms (-CH2 group).
- The difference in the molecular mass between two consecutive homologues is 14 amu.
- The physical properties of homologues show a regular gradation.
- Homologues of a series have similar chemical properties.
- Homologues of a series have similar methods of preparation.
Advantages of homologous series
The study of organic compounds becomes easier with the knowledge of homologous series. The study of a vast number of organic compounds become restricted to the study of a few series of homologues.
Examples of homologous series
Alkanes, alkenes, alkynes, alcohols, aldehydes, carboxylic acids etc. form separate homologous series.
