Alkenes — Paper 1 · IGCSE Sciences - Co-ordinated (Double) 0654

19 A petrochemical molecule undergoes the chemical change shown. H H H H H H H H H H H C C C C C H H C C C H + H C C H + H2 H H H H H H H H What is the chemical change? A cracking B fractional distillation C polymerisation D reduction

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2007

16 Large hydrocarbons can be ..….1…... to make smaller, more useful molecules. Small hydrocarbon molecules can be …...2…... to make long molecules. Which words correctly complete gaps 1 and 2? 1 2 A cracked distilled B cracked polymerised C distilled polymerised D distilled cracked

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2008

16 Which process produces molecules with longer chains? A combustion of hydrocarbon B cracking C fractional distillation of crude oil D polymerisation

1 marks

Answer: D

This question in 0654/11 May/June 2009

16 Catalytic cracking is useful in the petrochemical industry. Which two of the listed equations are possible cracking reactions? 1 2C8H18 → C16H34 + H2 2 C10H20 + H2 → C10H22 3 C10H22 → C10H20 + H2 4 C10H22 → C8H18 + C2H4 A 1 and 3 B 1 and 4 C 2 and 3 D 3 and 4

1 marks

Answer: D

This question in 0654/11 Oct/Nov 2009

18 Large hydrocarbons can be ..….1…... to make smaller, more useful molecules. Small hydrocarbon molecules can be …...2…... to make long molecules. Which words correctly complete gaps 1 and 2? 1 2 A cracked distilled B cracked polymerised C distilled polymerised D distilled cracked

1 marks

Answer: B

This question in 0654/12 May/June 2011

27 Ethanol can be made by reacting steam with a hydrocarbon. hydrocarbon + steam → ethanol H H H C C OH H H What is the name of the hydrocarbon? A ethane B ethene C methane D propene

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2013

27 Ethanol can be made by reacting steam with a hydrocarbon. hydrocarbon + steam → ethanol H H H C C OH H H What is the name of the hydrocarbon? A ethane B ethene C methane D propene

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2013

27 An alkane molecule undergoes the chemical change shown: H H H H H H H H H H H C C C C C H H C C C H + H C C H H H H H H H H H What is the name of the chemical change? A cracking B fractional distillation C polymerisation D reduction

1 marks

Answer: A

This question in 0654/13 May/June 2014

23 The structures of compounds X and Y are shown. H H H H H H H H C C C C H H H C C C C H H H H C C C C H H H H H H H compound X compound Y What are the correct formulae for these two compounds? compound X compound Y A C6H14 C6H10 B C6H14 C6H12 C C6H12 C6H10 D C6H12 C6H12

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2014

26 In which pair are both molecules unsaturated? H O H A H C C H C O H H O H H H H H H H B H C C C C C H H H H H H H C H C C H H C H H H H H H H H D H C C C H C H H H H

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2014

23 The diagram shows an experiment on a liquid hydrocarbon. liquid hydrocarbon on mineral wool catalyst ethene heat water Which change takes place? A combustion B cracking C fractional distillation D polymerisation

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2014

27 In which pair are both molecules unsaturated? H O H A H C C H C O H H O H H H H H H H B H C C C C C H H H H H H H C H C C H H C H H H H H H H H D H C C C H C H H H H

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2014

25 The diagram shows an experiment on a liquid hydrocarbon. liquid hydrocarbon on mineral wool catalyst ethene heat water Which change takes place? A combustion B cracking C fractional distillation D polymerisation

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2014

26 In which pair are both molecules unsaturated? H O H A H C C H C O H H O H H H H H H H B H C C C C C H H H H H H H C H C C H H C H H H H H H H H D H C C C H C H H H H

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2014

26 The hydrocarbon dodecane has the formula C12H26. Dodecane forms ethene and some ethane when it is heated. What is the name of the process? A cracking B distillation C evaporation D fractional distillation

1 marks

Answer: A

This question in 0654/12 May/June 2015

27 Ethanol is formed when steam reacts with compound Y. What is the name and what is the structure of compound Y? name structure H H A ethane C C H H H H B ethane H C C H H H H H C ethene C C H H H H D ethene H C C H H H

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2015

27 Organic molecule X has the following properties. ● Complete combustion produces carbon dioxide and water. ● It decolourises aqueous bromine water. ● It is produced by cracking. What is X? A ethane B ethene C ethanol D poly(ethene)

1 marks

Answer: B

This question in 0654/11 May/June 2016

27 Poly(ethene) and ethene are both hydrocarbons. Poly(ethene) is formed from ethene. Ethene turns aqueous bromine colourless, but poly(ethene) does not. Which statement is correct? A Ethene is a saturated hydrocarbon. B Ethene molecules are monomer units. C Only a few molecules of ethene are used to make poly(ethene). D Poly(ethene) is an unsaturated hydrocarbon.

1 marks

Answer: B

This question in 0654/12 May/June 2016

27 Ethene is formed when decane, C10H22, is passed over hot aluminium oxide. The aluminium oxide is unchanged in this process. decane on ceramic wool aluminium oxide ethene heat water Which terms describe the type of reaction and the role of the aluminium oxide? type of reaction role of aluminium oxide A cracking catalyst B cracking compound C fractional distillation catalyst D fractional distillation compound

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2016

27 Which structure represents an unsaturated hydrocarbon? A B C D H H H H H H H C C H C H H C C H H C C OH H H H H H H H

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2016

27 The structures of four hydrocarbons are shown. 1 2 H H H H H H H H C C C C H H C C C H H H H 3 4 H H H H H H H H C C C C C H H C C H H H H H H H H Which of the hydrocarbons change the colour of aqueous bromine? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: A

This question in 0654/12 Oct/Nov 2017

15 A hydrocarbon contains twice as many hydrogen atoms as carbon atoms. What is the formula of this compound? A C3H6 B C4H10 C C2H6O D C3H6O

1 marks

Answer: A

This question in 0654/11 May/June 2019

27 The flow diagram shows the manufacture of ethanol from alkanes. process X reagent Y alkane ethene ethanol What are process X and reagent Y? process X reagent Y A cracking hydrogen B cracking steam C fractional distillation hydrogen D fractional distillation steam

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2019

26 Which row describes properties of alkenes? products of structure of molecules complete combustion A contain only carbon and hydrogen CO2 and H2O B contain only carbon and hydrogen CO and H2O C contain only single bonds CO and H2O D contain only single bonds CO2 and H2O

1 marks

Answer: A

This question in 0654/12 May/June 2020

27 Poly(ethene) is a saturated hydrocarbon. It is formed by the addition polymerisation of ethene, H2C=CH2. Which diagram shows part of a molecule of poly(ethene)? A B H H H H H C C C C C C C C H H H H H C D H H H H H H H H C C C C C C C C H H H H H H H H

1 marks

Answer: D

This question in 0654/12 May/June 2021

27 Poly(ethene) is a saturated hydrocarbon. It is formed by the addition polymerisation of ethene, H2C=CH2. Which diagram shows part of a molecule of poly(ethene)? A B H H H H H C C C C C C C C H H H H H C D H H H H H H H H C C C C C C C C H H H H H H H H

1 marks

Answer: D

This question in 0654/13 May/June 2021

27 Which substance rapidly decolourises aqueous bromine? A ethane B ethanol C ethene D poly(ethene)

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2021

27 Which process produces alkenes from alkanes? A combustion B cracking C oxidation D reduction

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2021

27 Which statement about ethene, C2H4, is not correct? A It is an unsaturated hydrocarbon. B It is produced by cracking. C It is used to make a polymer. D It turns aqueous bromine brown.

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2021

27 Which substance is an unsaturated compound? A ethane B ethanol C ethene D methane

1 marks

Answer: C

This question in 0654/12 Feb/March 2023

27 Which substance reacts with ethene to produce ethanol? A bromine B hydrogen C oxygen D steam

1 marks

Answer: D

This question in 0654/12 Feb/March 2024

27 Which molecule reacts with aqueous bromine? A B C D H H H H H H H H H H C H C C C H H C C H H C C C H H H H H H H H H

1 marks

Answer: B

This question in 0654/11 May/June 2024

25 Which structure represents a compound that has a chemical name ending in ‘ene’? A B C D H H H H H H H H C H H C C O H H C C H C C H H H H H H H

1 marks

Answer: D

This question in 0654/12 Feb/March 2025

24 Which compound is an alkene? A B C D H H H H H H H H H C C H H C C O H C C C H H C H H H H H H H H

1 marks

Answer: C

This question in 0654/11 May/June 2025

25 The displayed formulas of four compounds are shown. H H H H H H H H C H H C C H C C H C C O H H H H H H H H 1 2 3 4 Which formulas represent ethanol and ethene? ethanol ethene A 4 2 B 1 3 C 4 3 D 2 1

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2025

25 The displayed formulas of four compounds are shown. H H H H H H H H C H H C C H C C H C C O H H H H H H H H 1 2 3 4 Which formulas represent ethanol and ethene? ethanol ethene A 4 2 B 1 3 C 4 3 D 2 1

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2025