Question

What is meant by homologous series of carbon compounds ? Write the general formula of (i) alkenes, and (ii) alkynes. Draw the structures of the first member of each series to show the bonding between the two carbon atoms.

Answer 1

A homologous series is a series of organic compounds that belong to the same family (i.e., possesses the same functional group) and show similar chemical properties. The members of this series are called homologues; they differ from each other by the number of CH₂ units in the main carbon chain. 

General Formula

AlkenesC_nH_2n:

Alkynes: C_nH_2n-2  

Structures

The first member of alkenes is ethene and its structure is given below.

The first member of alkynes is ethyne and its structure is given below :

H-C≡ C-H