Petrol contains octane, C8H18\mathrm{C_{8}H_{18}}C8H18. In a car engine, octane burns in air.
Write the balanced equation for the complete combustion of octane.
The relative formula mass of octane is 114. The volume of one mole of any gas at room temperature and pressure is 24 dm³.
Calculate the volume of oxygen, at room temperature and pressure, needed for the complete combustion of 57.0 g of octane.
Air contains about 20 % oxygen by volume. Calculate the volume of air needed.
When the air supply is limited, octane undergoes incomplete combustion and carbon monoxide forms. Balance the equation for this reaction.
...C8H18+...O2→...CO+...H2O\mathrm{C_{8}H_{18}} + ...\mathrm{O_{2}} \rightarrow ...\mathrm{CO} + ...\mathrm{H_{2}O}C8H18+...O2→...CO+...H2O
Explain, using your equations from (a) and (c), why carbon monoxide forms when the air supply is limited.
Explain two problems caused by the incomplete combustion of fuels in car engines.
37 exam-style questions on Edexcel GCSE Chemistry 9.1 Fuels, covering 9.1.1 Hydrocarbons and crude oil, 9.1.2 Fractional distillation of crude oil and its fractions, 9.1.3 The alkanes as a homologous series, 9.1.4 Complete and incomplete combustion, 9.1.5 Pollutants from burning fuels, 9.1.6 Hydrogen as a fuel and non-renewable fossil fuels, and 9.1.7 Cracking of larger alkanes. Each one has a worked solution and a mark scheme showing where the marks go.