The first member of alkyne homologous series is
(a) ethyne
(b) ethene
(c) propyne
(d) methane
Answer: (a)
Solution:
A homologous series is a group of organic compounds having similar structures and similar chemical properties in which the successive compounds differ by group.
The general formula of alkyne is where n is the number of carbon atoms. The first member of alkyne homologous series is ethyne as you need 2 carbons minimum to have a carbon connected with double bond.
Therefore, option (a) is correct.