- A series of carbon compounds in which same functional group substitutes the hydrogen atom is called a homologous series.
- These compounds have similar chemical properties due to the addition of same kind of functional group throughout the chain.
- For example, the series of alkanes i.e. Methane, ethane, propane, butane and so on is a homologous series.
- Similarly the series of alkene and alkynes also forms homologous series.
Homologous series of alkenes are as follows:
Homologous series of alkynes are as follows:
- The series like methanol, ethanol, propanol, butanol and so on is also a homologous series. The functional group attached to these compounds is alcohol.
- With the increase in molecular mass in a homologous series the physical properties like melting points, boiling points and solubility in a particular solvent increases.
- But the chemical properties of a homologous series determined by the functional group remain same.