The Combustion Reactions of Hydrocarbons and other Fuels

Hydrocarbons are organic compounds made up of hydrogen and carbon atoms only. These are mostly found in fuels such as coal, natural gas, and crude oil.
The combustion (burning) of hydrocarbons is an exothermic reaction, which means it releases energy in the form of heat and light.
In a complete combustion reaction, hydrocarbons react with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). The general equation for this reaction is: Hydrocarbon + Oxygen -> Carbon dioxide + Water
Incomplete combustion occurs when there is not enough oxygen present. This leads to the production of carbon monoxide (CO), water (H2O), and sometimes even soot or carbon (C).
Carbon monoxide is a poisonous gas which binds with the haemoglobin in our blood, preventing it from carrying oxygen around the body.
Soot or unburnt carbon particles contribute to global warming and can cause respiratory problems when inhaled.
The combustion of hydrocarbons also releases sulphur dioxide (SO2) and nitrogen dioxide (NO2), which are responsible for acid rain.
Biofuels, such as ethanol, can also undergo combustion. They are considered more environmentally friendly as they are renewable and produce less greenhouse gas emissions compared to fossil fuels.
Combustion reactions can be represented using balanced chemical equations. Ensure you can balance these equations, remembering the law of conservation of mass.
Energy efficiency and economic considerations are important in choosing fuels for different purposes. Factors to look at include cost, energy output, ease of storage and transport, and environmental impacts.
Clean fuels such as hydrogen and biofuels are being researched for use in transportation, as they produce fewer pollutants when burnt compared to hydrocarbon fuels.
Remember, the more hydrocarbons a fuel contains, the more energy it can produce when burnt - but also the more CO2 it produces. Choose wisely!
Revision of these topics should include understanding and applying these concepts, interpretation of relevant diagrams, and practising chemical equation balancing.