Fuels and Earth Science in Edexcel GCSE Chemistry

Suitable for GCSE Chemistry students studying from the Edexcel exam board

Hydrocarbons

Hydrocarbons

Compounds that contain carbon and hydrogen only.

Crude oil

A complex mixture of hydrocarbons.

Crude oil

Containing molecules in which carbon atoms are in chains or rings.

Crude oil

An important source of useful substances (fuels and feedstock for the petrochemical industry).

Crude oil

A finite resource.

Fractional distillation

The process of separating crude oil into simpler, more useful mixtures.

Boiling points

Different hydrocarbons have different boiling points; longer chain hydrocarbons have higher boiling points.

Fractionating column

A column where heated crude oil is piped in at the bottom, and the vaporised oil rises up and condenses at different levels.

Gases

Used for domestic heating and cooking.

Petrol

Fuel for cars.

Kerosene

Fuel for aircraft.

Diesel oil

Fuel for some cars and trains.

Fuel oil

Fuel for large ships and in some power stations.

Bitumen

Used for surface roads and roofs.

Alkane homologous series

A series of compounds that differ by CH2 in molecular formulae from neighbouring compounds.

Complete combustion

A reaction in which CO2 and H2O are produced and energy is given out (exothermic).

Incomplete combustion

Can produce carbon and carbon monoxide if there's not enough oxygen.

Carbon monoxide

A toxic gas that prevents red blood cells from carrying oxygen around the body, which can lead to death.

Soot

Causes global dimming.

Sulfur dioxide

Produced when impurities in some hydrocarbon fuels are burnt in oxygen.

Acid rain

Caused when sulfur dioxide dissolves in rain water, damaging buildings and reducing the growth of trees and crops.

Oxides of nitrogen

Pollutants produced when nitrogen and oxygen react together at high temperatures.

Hydrogen as fuel

Advantages include being a finite resource and only producing water, while disadvantages include being expensive and difficult to transport.

Cracking

The breaking down of larger, saturated hydrocarbon molecules (alkanes) into smaller, more useful ones, some of which are unsaturated (alkenes).

Demand for shorter chained alkanes

Much greater than that for longer chained alkanes; shorter chained hydrocarbons ignite more easily and are more useful as fuels.