sciencegcse← C7 overview

Chemistry · Paper 2 · Foundation + Higher · C7

Fractional distillation

Key ideas1 of 3

Separate by boiling point

Crude oil is heated so that most of it vaporises. The vapours enter a fractionating column, which is hot at the bottom and cooler at the top.

Fractionating column is cooler at the top and hotter at the bottom. Heated oil enters low down, vapours rise, fractions leave at different heights, gases leave the top and heavy residue leaves the bottom.

Next: Fuels and petrochemical feedstock →
Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Foundation + Higher · C7. All C7 lessons are shared by Foundation and Higher Tier.

AQA Combined Science Trilogy 8464 · 5.7.1.2. Original notes, questions and diagrams. Models are simplified, not to scale; illustrative data are labelled.