4.1 Fuels from Crude oil

Crude oil is formed over millions of years, from buried remains of plants and animals. 

We can separate a mixture of liquids by distillation. Distillation of crude oil produces liquids that boil within different temperature ranges, these liquids are called fractions. 

Crude oil is a mixture of many different compounds. Most of the compounds are hydrocarbon molecules which are made up of hydrogen and carbon.

Many of the hydrocarbons are alkanes, which have the general formula of: 

 CnH2n+2

Alkanes contain as many hydrogen atoms as possible in each molecule, therefore we call them saturates hydrocarbons.