plumiUses of chlorine and chlorate(I): AQA A‑Level Chemistry questions
AQA A-Level Chemistry past-paper questions on 3.2.3.2 Uses of chlorine and chlorate(I), 2008–2025, with mark schemes and examiner’s reports where available.
Paper
All papers
Exam
All years
Calculations
Q02.2
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ02.3
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFQ02.4
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFQ05.1
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ05.2
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFQ06.1
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ06.2
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFQ05.2
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ05.3
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFQ07.1
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ05.3
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ05.4
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFQ07.3
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ6(d)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ6(d)(ii)
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFQ1(c)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDF
All 38 questions on Uses of chlorine and chlorate(I), as a list
- June 2025, AS Paper 1, Q02.2 (2 marks): Chlorine is toxic but is added to drinking water. State why chlorine is added to drinking water. Explain why this is safe to do even though chlorine is toxic. [
- June 2025, AS Paper 1, Q02.3 (1 mark): Give an equation for the reaction of chlorine with water in sunlight. [1 mark]
- June 2025, AS Paper 1, Q02.4 (1 mark): Give the equation for the reaction between NaOH and Cl2 to form NaClO [1 mark]
- June 2024, Paper 1, Q05.1 (1 mark): Give an equation to show how chlorine forms an acidic solution in water. [1 mark]
- June 2024, Paper 1, Q05.2 (1 mark): Give an equation for the reaction between chlorine and cold, dilute aqueous sodium hydroxide. [1 mark]
- June 2024, AS Paper 1, Q13 (1 mark): Which species is never formed during the reactions of chlorine with water? [1 mark] A Chloride ions B Chlorate(I) ions C Hydrogen D Oxygen
- June 2022, Paper 1, Q06.1 (1 mark): Chlorine is added to some drinking water supplies to decrease the risk of people suffering from diseases such as cholera. State why the amount of chlorine added
- June 2022, Paper 1, Q06.2 (2 marks): Give an equation for the reaction of chlorine with water to form a solution containing two acids. Explain, with reference to electrons, why this is a redox reac
- June 2022, AS Paper 1, Q21 (1 mark): Which species is not a possible product of the reactions between chlorine and water? [1 mark] A Cl– B ClO– C O2 D OH–
- November 2021, AS Paper 1, Q05.2 (2 marks): Give an equation for the reaction of chlorine with water. Give a reason why chlorine is added to drinking water. [2 marks] Equation Reason
- November 2021, AS Paper 1, Q05.3 (1 mark): Chlorine reacts with cold, aqueous sodium hydroxide in the manufacture of bleach. Give an equation for this reaction. [1 mark]
- November 2020, Paper 3, Q16 (1 mark): Which shows the major product(s) formed when chlorine reacts with cold, dilute, aqueous sodium hydroxide? [1 mark] A NaCl only B NaClO only C NaCl and NaClO D N
- November 2020, AS Paper 1, Q07.1 (3 marks): Chlorine is used to treat water even though it is toxic to humans. Give one reason why water is treated with chlorine. Explain why chlorine is added to water ev
- June 2019, Paper 1, Q05.3 (1 mark): Chlorine reacts with hot aqueous sodium hydroxide as shown in the equation. 3 Cl2 + 6 NaOH → NaClO3 + 5 NaCl + 3 H2O Give the oxidation state of chlorine in NaC
- June 2019, Paper 1, Q05.4 (1 mark): State, in terms of redox, what happens to chlorine in the reaction in Question 05.3. [1 mark]
- June 2018, Paper 3, Q18 (1 mark): Chlorine reacts with cold, dilute, aqueous sodium hydroxide. Which is a complete list of the products? [1 mark] A Sodium chloride, sodium chlorate(I) and water
- June 2018, AS Paper 1, Q07.3 (1 mark): Chlorine is reacted with cold, aqueous sodium hydroxide in the manufacture of bleach. Give an equation for this reaction between chlorine and sodium hydroxide.
- June 2016, CHEM2 (old spec), Q6(d)(i) (1 mark): Write an equation for the formation of this equilibrium mixture. [1 mark]
- June 2016, CHEM2 (old spec), Q6(d)(ii) (2 marks): Household bleach contains sodium chlorate(I) and sodium chloride. State and explain, with reference to your equation in part (d)(i), why it is dangerous to acid
- June 2015, CHEM2 (old spec), Q1(c) (2 marks): In sunlight, chlorine can also oxidise water slowly to form oxygen. Write an equation for this reaction. Give the oxidation state of chlorine in the chlorine-co
- June 2014, CHEM2 (old spec), Q6(d)(i) (1 mark): Give one reason why water is treated with chlorine. [1 mark]
- June 2014, CHEM2 (old spec), Q6(d)(ii) (1 mark): Explain why the toxicity of chlorine does not prevent this use. [1 mark]
- June 2014, CHEM2 (old spec), Q6(d)(iii) (1 mark): Write an equation for the reaction of chlorine with cold water. [1 mark]
- June 2014, CHEM2 (old spec), Q6(e) (1 mark): Give the formulas of the two different chlorine-containing compounds that are formed when chlorine reacts with cold, dilute, aqueous sodium hydroxide. [1 mark]
- June 2013, CHEM2 (old spec), Q6(b) (1 mark): In bright sunlight, chlorine reacts with water to form oxygen as one of the products. Write an equation for this reaction. (1 mark)
- January 2013, CHEM2 (old spec), Q10(b) (3 marks): Write an equation for the reaction between chlorine and cold, dilute, aqueous sodium hydroxide. Give a major use for the solution that is formed by this reactio
- January 2013, CHEM2 (old spec), Q10(c) (2 marks): Write an equation for the equilibrium reaction that occurs when chlorine gas reacts with cold water. Give one reason why chlorine is used for the treatment of d
- June 2012, CHEM2 (old spec), Q9(b)(iii) (3 marks): The student knew that bromine can be used for killing microorganisms in swimming pool water. The following equilibrium is established when bromine is added to c
- June 2011, CHEM2 (old spec), Q3(c) (1 mark): Chlorine gas reacts with cold dilute sodium hydroxide solution to form sodium chloride and another chlorine-containing compound, X. Give the formula of X. (1 ma
- January 2011, CHEM2 (old spec), Q10(b)(ii) (2 marks): Deduce what happens to this equilibrium as the HClO reacts with bacteria in the water supply. Explain your answer.
- June 2010, CHEM2 (old spec), Q7(b)(i) (1 mark): Write an equation for this reaction. (1 mark)
- June 2010, CHEM2 (old spec), Q7(b)(ii) (2 marks): Give one large-scale application of the use of chlorine in water. Explain why it is used in this application even though chlorine is very toxic. Do not include
- June 2010, CHEM2 (old spec), Q7(b)(iii) (1 mark): Two different chlorine-containing compounds are formed when chlorine reacts with cold, dilute sodium hydroxide solution. One of these compounds is sodium chlori
- January 2010, CHEM2 (old spec), Q10(a) (3 marks): When chlorine gas dissolves in cold water, a pale green solution is formed. In this solution, the following equilibrium is established. Cl2(g) + H2O(l) H+(aq) +
- January 2010, CHEM2 (old spec), Q10(c) (3 marks): When chlorine reacts with water in bright sunlight, only two products are formed. One of these products is a colourless, odourless gas and the other is an acidi
- June 2009, CHEM2 (old spec), Q10(c) (4 marks): 10 (c) Bromine has been used for more than 70 years to treat the water in swimming pools. The following equilibrium is established when bromine is added to wate
- June 2008, CHM6W (2008 spec), Q26 (1 mark): 26 Substances that form acidic solutions when added to water include 1 AlCl3 2 Cl2 3 CH3COCl 4 NaCl
- January 2008, CHM2 (2008 spec), Q1(c) (2 marks): (c) Bromine reacts with cold aqueous sodium hydroxide. The reaction is similar to the reaction of chlorine with cold aqueous sodium hydroxide. Write an equation
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? AQA A-Level Chemistry past papers.
The Plumi iPad app also offers exam-style questions with AI feedback on your handwritten working.