This definitions covers Key Definitions within Crude Oil for GCSE Chemistry. Topic 37: Crude Oil It is section 7 of 13 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
📖 Key Definitions
Crude oil: A mixture of many different hydrocarbon molecules, formed over millions of years from the remains of dead marine organisms under high pressure and temperature. It is a finite, non-renewable resource.
Hydrocarbon: A compound containing carbon and hydrogen atoms only. Most hydrocarbons in crude oil are alkanes with the general formula CₙH₂ₙ₊₂.
Fraction: A group of hydrocarbon molecules with similar boiling points collected together during fractional distillation.
Fractional distillation: A physical process used to separate a mixture of liquids with different boiling points by controlled heating and condensation. No chemical bonds are broken.
Practice questions for Crude Oil
A hydrocarbon is a compound that contains only:
Explain how fractional distillation separates crude oil into different fractions.