plumiAlkanes: AQA A‑Level Chemistry questions
Every AQA A-Level Chemistry exam question on 3.3.2 Alkanes, 2016–2025, with its mark scheme and examiner’s report.
Find questions2,301
Calculations
Q01.1
The whole paper ↗![June 2025 Paper 2, question 01.1: Give the name of the mechanism for reaction 1. State one essential condition needed for reaction 1. [2 marks] Name of mechanism Essential condition](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74052-jun25-01-1-qp.webp)
Q01.2
The whole paper ↗![June 2025 Paper 2, question 01.2: Give equations to show three essential steps in the mechanism for reaction 1. [3 marks]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74052-jun25-01-2-qp.webp)
Q01.3
The whole paper ↗![June 2025 Paper 2, question 01.3: Suggest two reasons why using reaction 1 is likely to give a low yield of 1,2-dichlorobutane. [2 marks] Reason 1 Reason 2](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74052-jun25-01-3-qp.webp)
![June 2025 Paper 3, question 28: Alkanes are obtained from crude oil by fractional distillation. Which statement is correct? [1 mark] A Alkanes obtained are converted to alkenes by thermal crac](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74053-jun25-28-qp.webp)
![June 2025 AS Paper 2, question 09: Which statement about the combustion of petrol in vehicles is correct? [1 mark] A Exhaust gases can contain a mixture of unburned hydrocarbon molecules. B In th](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun25-09-qp.webp)
![June 2025 AS Paper 2, question 10: Which statement about catalytic cracking is correct? [1 mark] A A high percentage of alkenes is formed. B A pressure of about 70 MPa is used. C C–C bonds are br](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun25-10-qp.webp)
![June 2025 AS Paper 2, question 21: Which equation for the reaction of chlorine with excess ethane in the presence of ultraviolet light is correct? [1 mark] A C2H6 + 1 2 Cl2 → C2H5Cl + 1 2 H2 B C2](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun25-21-qp.webp)
Q03.1
The whole paper ↗
Q03.3
The whole paper ↗
Q03.5
The whole paper ↗
Q03.2
The whole paper ↗![June 2024 AS Paper 2, question 03.2: Give an equation for each of the two propagation steps in the conversion of CHFCl2 into CFCl3 [2 marks] Equation 1 Equation 2](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun24-03-2-qp.webp)
![June 2024 AS Paper 2, question 14: 1,1-Dichloroethane (Y) reacts with chlorine to form hexachloroethane (Z). Which is the correct equation for this reaction? [1 mark] A Y + 6 Cl2 → Z + 6 HCl B Y](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun24-14-qp.webp)
![June 2024 AS Paper 2, question 17: Which of these alkanes has the highest boiling point? [1 mark] A decane B hexane C 2,3-dimethyloctane D 2,3-dimethylbutane](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun24-17-qp.webp)
Q08.5
The whole paper ↗
Q02.1
The whole paper ↗![June 2023 AS Paper 2, question 02.1: Crude oil is separated into fractions by fractional distillation. State the meaning of the term ‘fraction’ in this context. [1 mark]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun23-02-1-qp.webp)
Q02.2
The whole paper ↗![June 2023 AS Paper 2, question 02.2: Petrol for cars contains branched and cyclic alkanes produced by catalytic cracking. Identify the catalyst used in this process. [1 mark]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun23-02-2-qp.webp)
Q02.4
The whole paper ↗![June 2023 AS Paper 2, question 02.4: Give the equation for the complete combustion of 3-ethyl-4-methylhexane. Use the molecular formula for 3-ethyl-4-methylhexane in your equation. [2 marks]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/74042-jun23-02-4-qp.webp)
Q02.6
The whole paper ↗
All 71 questions on Alkanes, as a list
- June 2025, Paper 2, Q01.1 (2 marks): Give the name of the mechanism for reaction 1. State one essential condition needed for reaction 1. [2 marks] Name of mechanism Essential condition
- June 2025, Paper 2, Q01.2 (3 marks): Give equations to show three essential steps in the mechanism for reaction 1. [3 marks]
- June 2025, Paper 2, Q01.3 (2 marks): Suggest two reasons why using reaction 1 is likely to give a low yield of 1,2-dichlorobutane. [2 marks] Reason 1 Reason 2
- June 2025, Paper 3, Q28 (1 mark): Alkanes are obtained from crude oil by fractional distillation. Which statement is correct? [1 mark] A Alkanes obtained are converted to alkenes by thermal crac
- June 2025, AS Paper 2, Q09 (1 mark): Which statement about the combustion of petrol in vehicles is correct? [1 mark] A Exhaust gases can contain a mixture of unburned hydrocarbon molecules. B In th
- June 2025, AS Paper 2, Q10 (1 mark): Which statement about catalytic cracking is correct? [1 mark] A A high percentage of alkenes is formed. B A pressure of about 70 MPa is used. C C–C bonds are br
- June 2025, AS Paper 2, Q16 (1 mark): Crude oil is separated into fractions in a fractionating column at an oil refinery. Which statement about the fractions collected higher up in the column, compa
- June 2025, AS Paper 2, Q21 (1 mark): Which equation for the reaction of chlorine with excess ethane in the presence of ultraviolet light is correct? [1 mark] A C2H6 + 1 2 Cl2 → C2H5Cl + 1 2 H2 B C2
- June 2024, Paper 2, Q03.1 (2 marks): Eicosane (C20H42) can be cracked by heating to 700 K in the presence of a catalyst. The products are • an aromatic hydrocarbon C8H10 • an alkane C6H14 • another
- June 2024, Paper 2, Q03.3 (1 mark): Cracking can also be done without a catalyst, using a temperature of 1200 K and a pressure of 7000 kPa State the type of product that is formed in high percenta
- June 2024, Paper 2, Q03.5 (2 marks): Natural gas is used in power stations to produce electricity. Natural gas contains sulfur impurities. Sulfur dioxide forms when these impurities are burned. Sta
- June 2024, AS Paper 2, Q03.2 (2 marks): Give an equation for each of the two propagation steps in the conversion of CHFCl2 into CFCl3 [2 marks] Equation 1 Equation 2
- June 2024, AS Paper 2, Q14 (1 mark): 1,1-Dichloroethane (Y) reacts with chlorine to form hexachloroethane (Z). Which is the correct equation for this reaction? [1 mark] A Y + 6 Cl2 → Z + 6 HCl B Y
- June 2024, AS Paper 2, Q16 (1 mark): Octadecane is a straight-chain alkane containing 18 carbon atoms per molecule. It is cracked to produce oct-1-ene and two other compounds. Which equation repres
- June 2024, AS Paper 2, Q17 (1 mark): Which of these alkanes has the highest boiling point? [1 mark] A decane B hexane C 2,3-dimethyloctane D 2,3-dimethylbutane
- June 2023, Paper 2, Q08.5 (2 marks): Complete combustion of the biofuel made from sewage sludge produces the greenhouse gas carbon dioxide. Suggest one other possible environmental problem with the
- June 2023, AS Paper 2, Q02.1 (1 mark): Crude oil is separated into fractions by fractional distillation. State the meaning of the term ‘fraction’ in this context. [1 mark]
- June 2023, AS Paper 2, Q02.2 (1 mark): Petrol for cars contains branched and cyclic alkanes produced by catalytic cracking. Identify the catalyst used in this process. [1 mark]
- June 2023, AS Paper 2, Q02.4 (2 marks): Give the equation for the complete combustion of 3-ethyl-4-methylhexane. Use the molecular formula for 3-ethyl-4-methylhexane in your equation. [2 marks]
- June 2023, AS Paper 2, Q02.6 (2 marks): Nitrogen monoxide (NO) is formed when petrol is burned in cars. State one environmental problem that NO causes. State what is used to remove NO from the exhaust
- June 2023, AS Paper 2, Q10 (1 mark): Which equation represents a propagation step in the chlorination of methane? [1 mark] A ●H + Cl2 → HCl + ●Cl B ●Cl + CH4 → CH3Cl + ●H C ●CH3 + Cl2 → CH3Cl + ●Cl
- June 2023, AS Paper 2, Q11 (1 mark): Which is the overall equation for the reaction of CCl3CH2CCl3 with an excess of chlorine in ultraviolet radiation? [1 mark] A CCl3CH2CCl3 + 1 2 Cl2 → CCl3CHClCC
- June 2022, Paper 2, Q10.3 (2 marks): Name the reagent for step 4. State a necessary condition for step 4. [2 marks] Reagent Condition
- June 2022, Paper 3, Q05.1 (2 marks): Zeolites are used as heterogeneous catalysts in the catalytic cracking of alkanes. Tetradecane (C14H30) can be cracked to form octane and a cycloalkane. Give an
- June 2022, Paper 3, Q22 (1 mark): 2-Bromopropane reacts with bromine to form 2,2-dibromopropane. What is the name of the mechanism of this reaction? [1 mark] A Electrophilic addition B Eliminati
- June 2022, AS Paper 2, Q06.2 (2 marks): An intermediate in this alternative synthesis is dichlorofluoromethane (CHCl2F) Give equations to represent the two propagation steps in the conversion of CHCl2
- June 2022, AS Paper 2, Q06.3 (1 mark): Analysis of the products of this reaction shows the formation of a compound with the empirical formula CCl2F Give an equation to represent a termination step fo
- June 2022, AS Paper 2, Q08 (1 mark): When hexadecane (C16H34) is heated to a high temperature, one molecule of hexadecane decomposes to form an alkane containing eight carbon atoms and two differen
- June 2022, AS Paper 2, Q09 (1 mark): The diagram shows a fractionating column used in the industrial fractional distillation of crude oil. Which statement is correct? [1 mark] A The most viscous pr
- November 2021, Paper 2, Q02.1 (1 mark): The petrol fraction obtained from crude oil can be used as fuel in cars. State the meaning of fraction, as used in the term petrol fraction. [1 mark]
- November 2021, Paper 2, Q02.2 (3 marks): Hexadecane (C16H34) can be cracked at high temperature to form petrol. Complete the equation to show the cracking of one molecule of hexadecane to form hexane a
- November 2021, Paper 2, Q09.4 (3 marks): Hydrochlorofluorocarbons (HCFCs) have been used in place of CFCs. In the mechanism to make an HCFC from a fluoroalkane, two incomplete steps are shown. Complete
- November 2021, AS Paper 2, Q05.1 (6 marks): The three key steps in the manufacture of poly(propene) from crude oil are shown. Naphtha is a mixture of alkanes with 6 to 12 carbon atoms per molecule. For ea
- November 2021, AS Paper 2, Q12 (1 mark): Which is a propagation step in the chlorination of methane? [1 mark] A H● + Cl2 → HCl + Cl● B Cl● + CH4 → CH3Cl + H● C ●CH3 + Cl● → CH3Cl D ●CH3 + Cl2 → CH3Cl +
- November 2021, AS Paper 2, Q22 (1 mark): Which statement is not correct about the pollutant sulfur dioxide? [1 mark] A It can be removed from car exhaust gases by a catalytic converter. B It can be rem
- November 2020, Paper 3, Q01.1 (2 marks): Explain how oxides of nitrogen are formed in engines. [2 marks]
- November 2020, Paper 3, Q01.2 (1 mark): State why it is desirable to decrease emissions of oxides of nitrogen from vehicles. [1 mark]
- November 2020, Paper 3, Q01.5 (1 mark): Some carbon particulates are also formed in both diesel and petrol vehicles. Explain why carbon particulates are formed. [1 mark]
- November 2020, Paper 3, Q23 (1 mark): Which is the mechanism for this conversion? [1 mark] A Addition-elimination B Electrophilic substitution C Free-radical substitution D Nucleophilic substitution
- November 2020, AS Paper 2, Q01.3 (3 marks): 1-chloropropane can also be produced by the reaction between propane and chlorine in the presence of ultraviolet light. State why ultraviolet light is needed fo
- November 2020, AS Paper 2, Q09 (1 mark): Which statement is correct about thermal cracking? [1 mark] A A pressure between 100 and 200 kPa is used. B Aromatic hydrocarbons are the major products. C C–C
- November 2020, AS Paper 2, Q14 (1 mark): An excess of methane reacts with chlorine in the presence of ultraviolet radiation. What are the main products of this reaction? [1 mark] A CCl4 and H2 B CCl4 a
- June 2019, Paper 2, Q11.4 (1 mark): Give an equation for the complete combustion of the ester C19H34O2 [1 mark]
- June 2019, AS Paper 2, Q04.1 (1 mark): The petrol fraction from crude oil contains octane (C8H18). Give an equation for the complete combustion of octane. [1 mark]
- June 2019, AS Paper 2, Q04.2 (1 mark): The combustion of petrol in car engines produces the pollutant nitrogen monoxide. Give an equation for a reaction that removes nitrogen monoxide in a catalytic
- June 2019, AS Paper 2, Q15 (1 mark): Which equation represents a propagation step? [1 mark] A •CH2Cl + Cl• CH2Cl2 B •CH3 + •CH3 C2H6 C Cl2 Cl• + Cl• D CH3Cl + Cl• •CH2Cl + HCl
- June 2018, Paper 2, Q01.1 (1 mark): Alkanes can be used as fuels. Give an equation for the combustion of heptane (C7H16) in an excess of oxygen. [1 mark]
- June 2018, Paper 2, Q01.2 (3 marks): Heptane can be obtained from the catalytic cracking of hexadecane (C16H34) at a high temperature. Identify a suitable catalyst for this process. Give one condit
- June 2018, Paper 2, Q01.3 (2 marks): Alkanes can be used in free-radical substitution reactions to produce halogenoalkanes. Give equations for the propagation steps in the reaction of butane to for
- June 2018, Paper 3, Q09 (1 mark): Which equation represents a termination step? [1 mark] A B C D
- June 2018, AS Paper 2, Q04.1 (2 marks): State the general formula of an alkane containing n carbon atoms. Deduce an expression for the relative molecular mass (Mr) of an alkane in terms of n. [2 marks
- June 2018, AS Paper 2, Q04.2 (2 marks): Explain why nonane has a higher boiling point than 2,4-dimethylheptane. [2 marks]
- June 2018, AS Paper 2, Q04.3 (1 mark): Give an equation for the complete combustion of nonane. [1 mark]
- June 2018, AS Paper 2, Q04.4 (2 marks): Nonane is often found in fuel for jet engines. Combustion in jet engines produces pollutants including nitrogen monoxide (NO). Explain how this nitrogen monoxid
- June 2018, AS Paper 2, Q04.5 (1 mark): Nonane can be cracked to form large quantities of propene. Name the type of cracking used. [1 mark]
- June 2018, AS Paper 2, Q14 (1 mark): Which statement is correct about the fractional distillation of crude oil? [1 mark] A A zeolite catalyst is used. B Each fraction contains a mixture of hydrocar
- June 2018, AS Paper 2, Q23 (1 mark): Which equation represents an initiation step? [1 mark] A B C D
- June 2017, Paper 3, Q08 (1 mark): The table shows possible conditions and products for the cracking of alkanes. Which row is correct? [1 mark] Type of cracking Conditions Products A Thermal High
- June 2017, AS Paper 2, Q04.1 (1 mark): Write an equation for the complete combustion of propane in oxygen. [1 mark]
- June 2017, AS Paper 2, Q15 (1 mark): Which equation is a propagation step in the conversion of trichloromethane into tetrachloromethane by reaction with chlorine in the presence of ultraviolet ligh
- June 2016, AS Paper 2, Q03.2 (3 marks): Octane and isooctane can be separated in the laboratory. Name a laboratory technique that could be used to separate isooctane from a mixture of octane and isooc
- June 2016, AS Paper 2, Q03.3 (1 mark): Isooctane is added to petrol to increase its octane rating. Some high-performance engines require fuel with a higher octane rating. Write an equation for the co
- June 2016, AS Paper 2, Q03.5 (1 mark): Carbon monoxide is produced when incomplete combustion takes place in engines. Nitrogen monoxide is another pollutant produced in car engines. Write an equation
- June 2016, AS Paper 2, Q05.4 (2 marks): One of the steps in the synthesis of 1,1,1-trifluoroethane (CF3CH3) is the reaction of 1,1-difluoroethane (CHF2CH3) with fluorine in a free-radical substitution
- June 2016, AS Paper 2, Q12 (1 mark): Sulfur dioxide (SO2) is produced when some fossil fuels are burned. Which of the following statements is true? [1 mark] A Sulfur dioxide can be removed from was
- June 2016, AS Paper 2, Q17 (1 mark): Tetradecane (C14H30) is an alkane found in crude oil. When tetradecane is heated to a high temperature, one molecule of tetradecane decomposes to form one molec
- Specimen, Paper 2, Q03.3 (1 mark): Isooctane can be formed, together with propene and ethene, in a reaction in which one molecule of an alkane that contains 20 carbon atoms is cracked. Using mole
- Specimen, Paper 2, Q03.4 (1 mark): How do the products of the reaction in Question 3.3 show that the reaction is an example of thermal cracking? [1 mark] 0 3 . 4
- Specimen, Paper 2, Q03.5 (2 marks): Number of monochloro isomers Structure
- Specimen, Paper 2, Q03.6 (1 mark): 0
- Specimen, Paper 3, Q25 (1 mark): Which molecule is not produced when ethane reacts with bromine in the presence of ultraviolet light? [1 mark] A C2H4Br2 B HBr C H2 D C4H10 2 5
Questions, mark schemes and examiner’s reports are © AQA, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? Every AQA A-Level Chemistry paper.
Rather write your answers by hand on iPad? Plumi marks them against the same mark schemes.