Question

Write the name and formula of the 3nd member of homologous series having general formula CnH2n – 2.

Answer 1

n=3
→C3H4
CH=_C-CH3
propyne

Answer 2

Since, methyne can't be the first member of alkyne series (CnH2n-2). So, the first member is ethyne. The series is given as:

1 - C2H2 (ethyne)

2 - C3H4 (propyne)

3 - C4H6 (butyne)

Therefore, the third member of alkyne series is Butyne with chemical formula C4H6.