Question

Write the molecular formula of an alkene and alkane with twenty carbon atoms.

Answer 1

The general molecular formula of an alkane is written as C_nH_2n+2, and the general formula of an alkene is written as C_nH_2n where ‘n’ is the number of carbon atoms. 

Now for n=20, the molecular formula of 

a) Alkane will be C₂₀H_2x20+2 or C₂₀H₄₂ 

b) Alkene will be C₂₀H_2x20 or C₂₀H₄₀