Which pair of formulae represents the same compound?
CH2=CHCH2CH3\mathrm{CH_{2}=CHCH_{2}CH_{3}}CH2=CHCH2CH3 and CH2=CHCH=CH2\mathrm{CH_{2}=CHCH=CH_{2}}CH2=CHCH=CH2
CH2=CHCH2CH3\mathrm{CH_{2}=CHCH_{2}CH_{3}}CH2=CHCH2CH3 and CH3CH2CH=CH2\mathrm{CH_{3}CH_{2}CH=CH_{2}}CH3CH2CH=CH2
CH3CH=CHCH3\mathrm{CH_{3}CH=CHCH_{3}}CH3CH=CHCH3 and CH2=C(CH3)2\mathrm{CH_{2}=C(CH_{3})_{2}}CH2=C(CH3)2
CH3CH=CHCH3\mathrm{CH_{3}CH=CHCH_{3}}CH3CH=CHCH3 and CH3CH2CH=CH2\mathrm{CH_{3}CH_{2}CH=CH_{2}}CH3CH2CH=CH2
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.