Hydrocarbons are the simplest organic compounds made purely of carbon and hydrogen
Most of the compounds in crude oil are hydrocarbons
The majority of these are alkanes
Alkanes have only single carbon-carbon bonds
They share the same general formula – CnH2n+2
Methane (CH4)
Ethane (C2H6)
Longer chain alkanes make poor fuels
They are viscous and don't easily burn
But longer chain alkanes can become more useful alkenes
Using catalytic cracking, which breaks covalent bonds, Alkenes always contain at least one carbon-carbon double bond
They share a formula too – CnH2n
Ethylene (C2H4)
Propylene (C3H6)
The double bond makes alkenes more reactive than their respective alkane
Alkenes can react further to make alcohols and polymers, like polyethylene
The most widely used plastic in the world