Alkenes — Paper 2 · IGCSE Chemistry (9-1) 0971

36 Which reaction is not a reaction which alkenes undergo? A bromination B hydration C hydrogenation D hydrolysis

1 marks

Answer: D

This question in 0971/21 May/June 2018

37 Which substances can be obtained by cracking hydrocarbons? A ethanol and ethene B ethanol and hydrogen C ethene and hydrogen D ethene and poly(ethene)

1 marks

Answer: C

This question in 0971/21 May/June 2018

36 Which two compounds are molecules which both contain a double bond? A ethane and ethanoic acid B ethane and ethanol C ethene and ethanoic acid D ethene and ethanol

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2018

37 Which products are obtained by the cracking of an alkane? alkene hydrogen water v v v 0 Oo WwW > v v x v x v x v v

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2019

37 Which molecule is not produced by an addition reaction of ethene? A CH3CH3 B CH2BrCH2Br C CH3CH2OH D CH3CH2CH3

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2020

38 P, Q, R and S are four organic compounds. P is an unsaturated hydrocarbon. Q burns but otherwise is unreactive. R contains a C–C single bond and a C=C double bond. S undergoes addition polymerisation. Which compounds are alkenes? A P and R only B P, R and S C P, Q and S D Q, R and S

1 marks

Answer: B

This question in 0971/21 May/June 2021

36 Which statement about ethene is correct? A It has the chemical formula C2H6. B It burns in excess oxygen producing carbon dioxide and water. C It reacts with Br2 to produce an orange solution. D It reacts with oxygen to form ethanol.

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2021

38 Which statements about unsaturated hydrocarbons are correct? 1 They contain both single and double bonds. 2 They turn aqueous bromine from colourless to brown. 3 They can be manufactured by cracking. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2021

37 Some properties of colourless liquid L are listed. ● It boils at 65 C. ● When added to water, two layers form which do not mix. ● It does not react with sodium carbonate. ● It has no effect on bromine water. What is L? A ethanol B hexane C hexene D ethanoic acid

1 marks

Answer: B

This question in 0971/21 May/June 2022

38 A molecule of compound P contains two carbon atoms and four hydrogen atoms. Which row represents P? name of reacts with compound aqueous bromine ethane ethene ethene ethene

1 marks

Answer: C

This question in 0971/21 May/June 2022

36 Ethene reacts with substance X to form ethanol. What is X? A ethanoic acid B glucose C hydrogen D steam

1 marks

Answer: D

This question in 0971/22 May/June 2022

37 Alkenes can be produced by cracking large hydrocarbon molecules to form smaller hydrocarbon molecules. Which equations represent possible reactions when tetradecane, C14H30, is cracked? 1 C14H30  C2H6 + C3H6 + C4H8 + C5H10 2 C14H30  H2 + C2H4 + C3H6 + C4H8 + C5H10 3 C14H30  C2H6 + 4C3H6 4 C14H30  C2H6 + C3H8 + C9H18 A 1 only B 1 and 4 C 1, 2 and 3 D 3 and 4

1 marks

Answer: C

This question in 0971/22 May/June 2022

38 The structures of some hydrocarbons are shown. 1 2 3 4 H H H H H H H H H H H C C H H C H H C C C H H C C C C H H H H H H H H H H H H H C C H H C C C H H H H H H Which statement about the hydrocarbons is correct? A 1 and 2 have a different general formula. B 1 and 4 are in different homologous series. C 2 and 3 are structural isomers. D 3 and 4 have the same empirical formula.

1 marks

Answer: D

This question in 0971/22 May/June 2022

36 Ethene reacts with both hydrogen and steam. Which row about these reactions is correct? reactant type of reaction catalyst used with ethene A hydrogen substitution phosphoric acid B hydrogen addition nickel C steam substitution phosphoric acid D steam addition nickel

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2022

39 Which statement about unsaturated hydrocarbons is correct? A CH3CH2CH=CHCH3 is an unsaturated hydrocarbon. B Ethene has more hydrogen atoms per molecule than ethane. C Unsaturated hydrocarbons have double bonds between carbon and hydrogen atoms. D Unsaturated hydrocarbons turn aqueous bromine from colourless to brown.

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2022

35 Which equation represents the cracking of an alkane? A 3C2H4 → C6H12 B C6H12 + H2 → C6H14 C C6H14 → 6C + 7H2 D C6H14 → C2H4 + C4H10

1 marks

Answer: D

This question in 0971/21 May/June 2023

36 What is the structure of the product of the reaction of propene with bromine? A B C D H H H H Br H H Br H H H H H C C C Br H C C C H C C C Br Br C C C Br H H H H Br H H H H H H

1 marks

Answer: C

This question in 0971/21 May/June 2023

30 The hydrocarbon C4H8 has two structural isomers, but-1-ene and but-2-ene. Which statement is correct? A But-2-ene has the structural formula CH3CH=CHCH3 and the same general formula as butane. B But-2-ene has the structural formula CH3CH=CHCH3 and the same empirical formula as ethene. C But-1-ene has the structural formula CH3CH2CH=CH2 and the same general formula as butane. D But-1-ene has the structural formula CH3CHCH2=CH and the same empirical formula as ethene.

1 marks

Answer: B

This question in 0971/22 May/June 2023

31 Which compound rapidly decolourises aqueous bromine? A propane B propanoic acid C propanol D propene

1 marks

Answer: D

This question in 0971/22 May/June 2023

32 What are the products of the addition reactions of ethene with bromine and hydrogen? bromine hydrogen A CH2BrCH2Br CH3CH3 B CH2BrCH2Br CH2CH2 C CH3CH2Br CH3CH3 D CH3CH2Br CH2CH2

1 marks

Answer: A

This question in 0971/22 May/June 2023

36 The structure of an organic compound is shown. H H H H C C C O H H H H Which structure represents a molecule that reacts with steam to produce this product? A B C D H H H H H H H H H H C C H C C C H H C C O H H C C C H H H H H H H H H

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2023

33 Which formula represents an alkene? A CH4 B C2H4 C C2H6 D C2H5OH

1 marks

Answer: B

This question in 0971/22 May/June 2024

37 Alkenes react with steam in an addition reaction. Some alkenes produce only one alcohol product. Some alkenes produce two different alcohols which are structural isomers. Which row gives the number of alcohol isomers formed when ethene reacts with steam and when propene reacts with steam? number of alcohol isomers formed ethene + steam propene + steam A 1 1 B 1 2 C 2 1 D 2 2

1 marks

Answer: B

This question in 0971/22 May/June 2024

29 Bromine reacts with but-2-ene. What is the displayed formula of the product of this reaction? A B H Br H H H H H H H C C C C H H C C C C H H Br H H Br Br H H C D H H H H H H H H H C C C C H H C C C C H H Br Br H Br H H Br

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2024

35 Which equation represents an addition reaction? A CH3CHO + HCN  CH3CH(OH)CN B C6H6 + Br2  C6H5Br + HBr C NH4Br  NH3 + HBr D C14H30  C2H4 + C8H18 + C4H8

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2024

32 The alkenes are a homologous series. Which statement about the members of the homologous series of the alkenes is correct? A They have the same functional group. B They have the same relative molecular mass. C They have different chemical properties. D They have different general formulae.

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2025

36 Which row shows the products obtained by the cracking of a large alkane? alkene hydrogen water v v v key /=yes 0 0O WwW > J Jv x Jv x Jv X=no x Jv J

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2025

38 Propenoic acid is an organic compound that is both an alkene and a carboxylic acid. The structure of propenoic acid is shown. H H O C C C H OH Which structure represents one repeat unit of the addition polymer formed from propenoic acid? A B C D CH3 O H COOH H H O CH3 COOH C C O C C C C C O C C H H H H H H H

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2025