Alkenes

Alkenes are unsaturated hydrocarbons with atleast 1 C=C double bond.

• Aliphatic alkenes with one double bond have the general formula: C H
• Alkenes are more reactive than alkanes, and typically take part in addition reactions
• Alkenes can form E/Z isomers, including cis-trans isomers

Ethene is a very important alkenes. It is obtained from the cataytic cracking of crude oil fractions. Ethene is used to make polymers for the plastics industry. The C=C bond is the functional group in an alkene and is responsible for its reactions. 

The nature of the double bond

The C=C double bond is made up from two parts; a sigma,  , bond and a pi,  , bond,  -bonds are also present in alkanes.

In the formation of the double bond:

• A  -bond  is formed directly between two carbon atoms by the overlap of orbitals. Each carbon atom contributes one electron to…