Question

i. Write the general molecular formula of alkenes. 

ii. Why are alkenes also known as olefins?

Answer 1

i. Alkenes have general formula C_nH_2n , where, n = 2,3,4… etc. 

ii. Alkenes are also known as olefins because the first member ethene/ethylene reacts with chlorine to form oily substance. 

[Note: Alkenes with one carbon-carbon double bond, contain two hydrogen atoms less than the corresponding alkanes.]