Explain how crude oil is separated into fractions (6 marks)

Crude oil is separated into fractions in a process called fraction distillation. The crude oil mixture is separated in a distillation column. The column is hot at the bottom and cool at the top. Fractional distillation works because the different compounds within the crude oil mixture have different boiling points. The crude oil mixture is fed into the bottom of the column as a gas. The substances with high boiling points condense at the bottom and can be removed from the column as liquids and the substances with low boiling points condense at the top.