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Methane is an alkane. An alkane is a saturated hydrocarbon. State how a saturated hydrocarbon differs from an unsaturated hydrocarbon.
See it on the paper →Describe what is meant by unsaturated and hydrocarbon. unsaturated hydrocarbon
See it on the paper →State the type of bond in a molecule of but-1-ene. Choose from the list. covalent intermolecular ionic metallic
See it on the paper →has a carbon-carbon double bond (C=C).
See it on the paper →Propene is an unsaturated hydrocarbon. Explain why.
See it on the paper →Propene is an unsaturated hydrocarbon. Explain the terms unsaturated and hydrocarbon. unsaturated hydrocarbon
See it on the paper →Complete the displayed formula for but-2-ene. C C C C
See it on the paper →State which compound is propene. Choose from A, B, C or D.
See it on the paper →Comprehensive responses • Some candidates recognised the description of an alkene and correctly identified ethene. Limited responses • Some candidates confused alkenes with alkanes and suggested either methane or ethane.
— Examiner report, February/March 2026, 0654/32 Q5(a)(v) (Cambridge)
Comprehensive responses • Many candidates described the presence of a double bond as indicating that propene is unsaturated. Limited responses • Some candidates omitted the presence of hydrogen and carbon atoms. • Some candidates described the presence of hydrogen and carbon molecules rather than atoms. • Some candidates did not include that hydrocarbons are only made of carbon and hydrogen atoms...
— Examiner report, February/March 2026, 0654/42 Q7(a) (Cambridge)
Most candidates identified propene. B and D were popular incorrect responses.
— Examiner report, May/June 2025, 0654/43 Q7(a)(ii) (Cambridge)
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State the difference between a saturated hydrocarbon and an unsaturated hydrocarbon.
Cracking is a process that produces small alkene molecules from larger alkane molecules. Ethane is an alkane. Ethene is an alkene. Fig. 8.2 shows the structure of ethane, C 2 H 6 . H H H C C H H H Fig. 8.2 Draw the structure of ethene, C 2 H 4 .
See it on the paper →State which compound A, B, C, or D is unsaturated.
See it on the paper →Which row describes the hydrocarbon CH 3CHCH2?
See it on the paper →State which of the molecules P, Q, R or S is an alkene.
See it on the paper →State the difference in structure between an alkane and an alkene.
See it on the paper →Propene is an unsaturated hydrocarbon. State what is meant by the word unsaturated.
See it on the paper →State how the molecular structure of an alkane molecule differs from the molecular structure of an alkene molecule.
See it on the paper →State what is meant by the term unsaturated compound.
See it on the paper →Fig. 8.2 shows the structure of a small molecule called propene. H H H C C H C H H Fig. 8.2 Propene is an alkene. It is unsaturated. Explain why propene is unsaturated.
See it on the paper →Table 8.1 shows the structures of some small molecules and long chain molecules. Complete Table 8.1. Table 8.1 name of small molecule structure of small molecule H H ethene H H propene H H H H H H H H C C C C C C H C H C H H H H H H structure of long chain molecule C C H H H H C C C C H H H H H H H n n H H H C C H Cl C...
See it on the paper →Explain why molecule X is unsaturated.
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