Question

Which of the following is an example of homologous series?

• A. Methane, Ethane, Propene, Butane
• B. Methanal, Ethanal, Propanol, Butanal
• C. Methanol, Ethanol, Propanol, Butanol
• D. Ethane, Propane, Butane, Pentene

Answer 1

The correct option is C Methanol, Ethanol, Propanol, Butanol

A homologous series is a series of carbon compounds that have different number of carbon atoms but contain the same functional group and the consecutive members differ by a ${\text{CH}}_2$ group.

Methanol, ethanol, propanol and butanol are all alcohols and hence, belong to the same homologous series. They differ from each other by one ${\text{CH}}_2$ group.

In all the other options, even though they have same functional groups, the type of C-C bonds are different.