Alkanes — Paper 2 · IGCSE Sciences - Co-ordinated (Double) 0654

26 Which structure represents a molecule of butane? A B H H H H H H H H C C C C H H C C C H H H H H H H H C D H H H H H H H H C C C H C C C C H H H H H

1 marks

Answer: A

This question in 0654/22 May/June 2017

27 The structure of a hydrocarbon is shown. H H H H C C C H H H H What is the name of this hydrocarbon? A butane B butene C propane D propene

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2017

26 Which diagram represents a molecule of ethane? A B C D H H H H H H H H C H C C H C C H H C C O H H H H H H H H

1 marks

Answer: C

This question in 0654/22 Oct/Nov 2019

27 One molecule of hydrocarbon Q undergoes complete combustion to produce four molecules of carbon dioxide. Hydrocarbon Q has no effect on the colour of bromine water. What is hydrocarbon Q? A butane B butene C propane D propene

1 marks

Answer: A

This question in 0654/22 Oct/Nov 2019

26 The structures of three organic compounds are shown. CH2 CH2 CH3 CH2 CH2 CH3 CH3 CH3 CH3 CH2 CH3 CH2 CH2 Which statement about these three compounds is correct? A They are alcohols. B They are alkenes. C They are saturated. D They do not burn.

1 marks

Answer: C

This question in 0654/21 May/June 2020

26 The same mass of five different alkanes are left to evaporate under identical conditions. The mass lost by each alkane in one day is measured. Which graph shows the mass lost against the number of carbon atoms in each alkane chain? A B mass mass lost lost 9 10 11 12 13 9 10 11 12 13 number of carbon atoms number of carbon atoms in alkane chain in alkane chain C D mass mass lost lost 9 10 11 12 13 9 10 11 12 13 number of carbon atoms number of carbon atoms in alkane chain in alkane chain

1 marks

Answer: A

This question in 0654/21 May/June 2022

26 Hydrocarbon X has two carbon atoms in each molecule. It does not decolourise bromine water. Hydrocarbon Y has three carbon atoms in each molecule. It does decolourise bromine water. What is the difference in the number of hydrogen atoms in the molecules of X and Y? A 0 B 1 C 2 D 4

1 marks

Answer: A

This question in 0654/22 Feb/March 2023

26 A gasoline fraction from the fractional distillation of petroleum includes compounds with the formulas C6H14 and C12H26. Which statements about these compounds are correct? 1 C12H26 has a higher boiling point than C6H14. 2 C12H26 has a lower relative molecular mass than C6H14. 3 C6H14 and C12H26 are members of different homologous series. 4 C6H14 and C12H26 both undergo complete combustion to form carbon dioxide and water. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4 O

1 marks

Answer: B

This question in 0654/22 May/June 2024

27 Reactants for three chemical processes are listed. 1 ethene + steam 2 ethene + hydrogen 3 ethene forming poly(ethene) Which processes form saturated hydrocarbons? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: D

This question in 0654/23 Oct/Nov 2024

25 A molecule of methane contains one carbon atom and has the formula CH4. A molecule of octane contains eight carbon atoms. How many hydrogen atoms are in a molecule of octane? A 11 B 16 C 18 D 32

1 marks

Answer: C

This question in 0654/22 May/June 2025

25 The structures of four organic compounds, P, Q, R and S, are shown. H H H H H H H C C H C C C C C H H H H H H P Q H H H H H H H H H H H H C C C C C H H C C C C C C H H H H H H H H H H H H R S Which statements about P, Q, R and S are correct? 1 P and Q have the same general formula. 2 Q and R have similar chemical properties. 3 R and S are members of the same homologous series. 4 R and Q have the same molecular mass, Mr. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: B

This question in 0654/23 Oct/Nov 2025