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

30 Which statements about water are correct? 1 Household water contains dissolved salts. 2 Water for household use is filtered to remove soluble impurities. 3 Water is treated with chlorine to kill bacteria. 4 Water is used in industry for cooling. A 1, 2, 3 and 4 B 1, 2 and 3 only C 1, 3 and 4 only D 2, 3 and 4 only

1 marks

Answer: C

This question in 0971/21 May/June 2018

33 Which statement about sulfur or one of its compounds is correct? A Sulfur occurs naturally as the element sulfur. B Sulfur dioxide is used to kill bacteria in drinking water. C Sulfuric acid is a weak acid. D Dilute sulfuric acid is a dehydrating agent.

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2018

28 Water can be treated by filtration then chlorination. Which uses do not need water of this quality? 1 water for cooling in industry 2 water for washing clothes 3 water for drinking A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: B

This question in 0971/21 May/June 2019

30 River water contains soluble impurities, insoluble impurities and bacteria. River water is made safe to drink by filtration and chlorination. Which statement is correct? A Filtration removes bacteria and insoluble impurities, and chlorination removes soluble impurities. B Filtration removes insoluble impurities, and chlorination kills the bacteria. C Filtration removes soluble and insoluble impurities, and chlorination kills the bacteria. D Filtration removes soluble impurities and bacteria, and chlorination removes insoluble impurities.

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2019

29 Which statement about pure water is not correct? A It condenses at 100 °C. B It freezes at 0 °C. C It turns cobalt(II) chloride paper blue. D It turns anhydrous copper(II) sulfate blue.

1 marks

Answer: C

This question in 0971/22 May/June 2020

29 Water is used for the irrigation of crops and for drinking water. For which uses must water be chlorinated? irrigation drinking v v 0 0O WwW > v x x v x x

1 marks

Answer: C

This question in 0971/22 May/June 2021

32 Lime (calcium oxide) is used to treat waste water from a factory. Which substance is removed by the lime? A ammonia B sodium chloride C sodium hydroxide D sulfuric acid

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2021

29 The diagram shows the uses and treatment processes of muddy river water. process 1 process 2 muddy river water clear river water disinfected water use 1 use 2 Which row identifies uses 1 and 2 and processes 1 and 2? use 1 use 2 process 1 process 2 A drinking watering crops chlorination filtration B drinking watering crops filtration chlorination C watering crops drinking chlorination filtration D watering crops drinking filtration chlorination

1 marks

Answer: D

This question in 0971/21 May/June 2022

28 The diagram shows a stage in the purification of dirty water. dirty water sand pot with holes fine gravel in bottom coarse gravel Which process does this apparatus show? A chlorination B condensation C distillation D filtration

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2022

29 Several processes are used to treat domestic water. Which row identifies a reason for the given process? process reason A chlorination removes impurities B filtration removes insoluble solids C sedimentation removes soluble solids D use of carbon kills bacteria

1 marks

Answer: B

This question in 0971/21 May/June 2023

30 The flow chart shows stages in the treatment of river water to produce drinking water. river sedimentation stage stage drinking water tank J K water What occurs at stages J and K? J K A distillation chlorination B distillation filtration C filtration chlorination D filtration distillation

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2023

34 Which statement identifies a sample of water as pure? A It melts at room temperature. B It turns anhydrous copper(II) sulfate blue. C It turns hydrated cobalt(II) chloride from blue to pink. D It boils at 100°C.

1 marks

Answer: D

This question in 0971/21 May/June 2024

27 Which statements about the treatment of domestic water supplies are correct? 1 Filtration is used to remove insoluble substances from the water. 2 Sedimentation is used to remove soluble substances from the water. 3 Carbon is used to remove tastes and odours from the water. 4 Chlorine is used to lower the pH of the water. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: A

This question in 0971/22 May/June 2024

28 Which statement about water is correct? A It turns anhydrous copper(II) sulfate from pink to blue. B It turns anhydrous copper(II) sulfate from white to blue. C It turns cobalt(II) chloride paper from blue to white. D It turns cobalt(II) chloride paper from pink to blue.

1 marks

Answer: B

This question in 0971/22 May/June 2024

30 Which flow chart describes the correct treatment sequence of the domestic water supply? A filtration  chlorination  sedimentation B sedimentation  chlorination  filtration C chlorination  filtration  sedimentation D sedimentation  filtration  chlorination

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2025