Alkenes are a homologous series of hydrocarbons. Ethene, C2H4\mathrm{C_{2}H_{4}}C2H4, is used to make plastics, and propene is used to make ropes and food containers.
Give the formula of propene.
Name the functional group present in all alkenes.
Explain why alkenes are described as unsaturated.
Butene can exist as two different molecules, but-1-ene and but-2-ene. Their condensed structures are:
but-1-ene CH2=CHCH2CH3\mathrm{CH_{2}=CHCH_{2}CH_{3}}CH2=CHCH2CH3 and but-2-ene CH3CH=CHCH3\mathrm{CH_{3}CH=CHCH_{3}}CH3CH=CHCH3
Give the molecular formula of both but-1-ene and but-2-ene.
Describe how the structure of but-1-ene is different from the structure of but-2-ene.
The general formula of the alkenes is CnH2n\mathrm{C_{n}H_{2n}}CnH2n. Give the formula of the alkene with 6 carbon atoms.
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.