Which of these mixtures contains only the formulae of substances that would represent components of the refinery gas (gaseous) fraction of crude oil?
CH3OH\text{CH}_3\text{OH}CH3OH, C2H6\text{C}_2\text{H}_6C2H6, C3H8\text{C}_3\text{H}_8C3H8
CH4\text{CH}_4CH4, C2H5Cl\text{C}_2\text{H}_5\text{Cl}C2H5Cl, C3H8\text{C}_3\text{H}_8C3H8
CH4\text{CH}_4CH4, C2H6\text{C}_2\text{H}_6C2H6, C3H8\text{C}_3\text{H}_8C3H8
CH4\text{CH}_4CH4, C2H6\text{C}_2\text{H}_6C2H6, C3H7OH\text{C}_3\text{H}_7\text{OH}C3H7OH
105 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.