Two molecules of a fuel react with exactly ten molecules of oxygen, O2\mathrm{O_{2}}O2, in complete combustion. Carbon dioxide and water are the only products, and no reactant is left over.
Which fuel is it?
Propane, C3H8\mathrm{C_{3}H_{8}}C3H8
Propan-1-ol, C3H7OH\mathrm{C_{3}H_{7}OH}C3H7OH
But-1-ene, C4H8\mathrm{C_{4}H_{8}}C4H8
Propene, C3H6\mathrm{C_{3}H_{6}}C3H6
131 exam-style questions on OCR GCSE Chemistry 6.2 Organic chemistry, covering 6.2.1 Crude oil and fractional distillation, 6.2.2 Cracking and dependence on hydrocarbons, 6.2.3 Functional groups and homologous series, 6.2.4 Reactions of alkanes, alkenes and alcohols, 6.2.5 Addition polymerisation and repeat units, 6.2.6 Naturally occurring polymers, 6.2.7 Chemical cells and fuel cells, and 6.2.8 Condensation polymerisation and how to make one. Each one has a worked solution and a mark scheme showing where the marks go.