Homologous series :
The series of carbon compounds in which two successive compounds differ by – CH2 unit is called homologous series.
Characteristic features of homologous series :
1. They have one general formula. Ex : Alkane (C4 H2n+2), Alkene (C4 H2n), Alkyne (C4 H2n-2)
2. Successive compounds in their series possess a difference of (- CH2) unit.
3. They possess similar chemical properties due to the same functional group.
4. They show a regular gradation in their physical properties.
