Question

Write the structural formulas for an alkane and alkene and an alkyne

Answer 1

The structural formula for an alkane is CnH(2n+2).
For example ethane C2H6, here n=2.

The structural formula for an alkene is CnH2n
For example ethene C2H4, here n=4.

The structural formula for alkyne is C2H2.
For example ethyne C2H2, here n=2.

Answer 2

alkane - CnH2n+2  where n =  1 , 2 , 3...    eg   if n= 1 CH4

                                                                              n=2  C2H6

alkene -CnH2n    where n = 1 ,2 ,3....

Alkyne-CnH2n-2 where n =1 ,2 ,3.....