A hydrocarbon contains 83.3% carbon by mass.
Which of these is its molecular formula?
(relative atomic masses: C = 12, H = 1)
C4H10\mathrm{C_{4}H_{10}}C4H10
C5H10\mathrm{C_{5}H_{10}}C5H10
C6H14\mathrm{C_{6}H_{14}}C6H14
C5H12\mathrm{C_{5}H_{12}}C5H12
36 exam-style questions on Edexcel GCSE Chemistry 10.2 Hydrocarbons, covering 10.2.1 Formulae and structures of the alkanes, 10.2.2 Alkenes and the C=C functional group, 10.2.3 Addition reactions of alkenes and testing for unsaturation, and 10.2.4 Combustion of alkanes and alkenes. Each one has a worked solution and a mark scheme showing where the marks go.