Fuel P is a hydrocarbon. When one molecule of P undergoes complete combustion, it forms three molecules of carbon dioxide and four molecules of water.
Fuel Q is an alcohol with the formula C4H9OH\mathrm{C_4H_9OH}C4H9OH.
A fuel sample contains three molecules of P and two molecules of Q.
Calculate how many molecules of oxygen, O2\mathrm{O_2}O2, are needed for the complete combustion of one molecule of each fuel.
Calculate the total number of molecules of oxygen needed for the complete combustion of the fuel sample.
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.