4.8 describe how the industrial process of fractional distillation separates crude oil into fractions

 Process:
- Crude oil is separated by fractional distillation.
- Crude oil is heated and oil evaporates.
- It then goes into the tower. As the vapours rise up the tower, the temperature falls.
- Different sized fractions condense at different heights because they have different boiling points.
- Smaller molecules condense high up the tower. Larger molecules condense low down the tower.
- Fractions are collected in liquid form.