The characteristic properties of acids and bases — Paper 2 · IGCSE Sciences - Co-ordinated (Double) 0654

19 The pH of water changes when ammonia is bubbled into it. What happens to the pH and why? pH ammonia is A decreases acidic B decreases alkaline C increases acidic D increases alkaline

1 marks

Answer: D

This question in 0654/21 May/June 2017

23 Four solutions are tested with Universal Indicator paper and with anhydrous copper(II) sulfate. Which row shows the observations for pure water? Universal Indicator paper anhydrous copper(II) sulfate A turns blue turns blue B turns blue turns white C turns green turns blue D turns green turns white

1 marks

Answer: C

This question in 0654/21 May/June 2017

25 Why do farmers add lime to soil? A It acts as a fertiliser. B It adds nitrogen to the soil. C It decreases the pH of the soil. D It increases the pH of the soil.

1 marks

Answer: D

This question in 0654/21 May/June 2017

19 The pH of water changes when ammonia is bubbled into it. What happens to the pH and why? pH ammonia is A decreases acidic B decreases alkaline C increases acidic D increases alkaline

1 marks

Answer: D

This question in 0654/22 May/June 2017

25 Why do farmers add lime to soil? A It acts as a fertiliser. B It adds nitrogen to the soil. C It decreases the pH of the soil. D It increases the pH of the soil.

1 marks

Answer: D

This question in 0654/22 May/June 2017

19 The pH of water changes when ammonia is bubbled into it. What happens to the pH and why? pH ammonia is A decreases acidic B decreases alkaline C increases acidic D increases alkaline

1 marks

Answer: D

This question in 0654/23 May/June 2017

25 Why do farmers add lime to soil? A It acts as a fertiliser. B It adds nitrogen to the soil. C It decreases the pH of the soil. D It increases the pH of the soil.

1 marks

Answer: D

This question in 0654/23 May/June 2017

21 Aqueous solutions of oxides X, Y and Z are tested using Universal Indicator. Oxide X turns the indicator red. Oxide Y turns the indicator blue. Oxide Z turns the indicator green. Which row describes these three substances? X Y Z A acidic basic basic B acidic basic neutral C basic acidic acidic D basic acidic neutral

1 marks

Answer: B

This question in 0654/23 Oct/Nov 2018

19 An acid is added to an alkali until the final solution is just neutral. The reaction is exothermic. Which graph shows how the temperature changes as the acid is being added to the alkali? A B start start temperature temperature 0 volume of acid 0 volume of acid C D start start temperature temperature 0 volume of acid 0 volume of acid

1 marks

Answer: C

This question in 0654/23 May/June 2019

21 The pH values of four liquids are 1, 4, 7 and 13. The four liquids are distilled water, nitric acid, potassium hydroxide and vinegar. Which row shows the pH values of the liquids? potassium distilled water nitric acid vinegar hydroxide A 4 7 13 1 B 4 13 7 1 C 7 1 4 13 D 7 1 13 4

1 marks

Answer: D

This question in 0654/21 Oct/Nov 2019

20 An acid neutralises solution X. A neutral solution is formed. What are the pH values of solution X and of the neutral solution? pH of solution X pH of neutral solution A 2 7 B 2 12 C 12 2 D 12 7

1 marks

Answer: D

This question in 0654/22 Oct/Nov 2019

25 Limestone is converted to lime in process 1. Limestone is used to treat industrial waste in process 2. What are processes 1 and 2? process 1 process 2 A decomposition dissolving B decomposition neutralisation C oxidation dissolving D oxidation neutralisation

1 marks

Answer: B

This question in 0654/21 May/June 2020

25 Which statement about calcium carbonate is not correct? A It forms carbon dioxide when it is heated. B It forms carbon dioxide when it is mixed with dilute hydrochloric acid. C It is formed by heating lime. D It neutralises acids.

1 marks

Answer: C

This question in 0654/22 May/June 2020

20 A label from a packet of indigestion tablets is shown. Each tablet contains: magnesium carbonate 120 mg magnesium hydroxide 15 mg magnesium oxide 62 mg magnesium sulfate 47 mg Which substance does not neutralise stomach acid? A magnesium carbonate B magnesium hydroxide C magnesium oxide D magnesium sulfate

1 marks

Answer: D

This question in 0654/22 Feb/March 2021

20 What reacts with ammonia gas? hydrochloric sodium acid hydroxide A Jv J B Jv x Cc x v D x x key Jv = reacts X = does not react

1 marks

Answer: B

This question in 0654/21 May/June 2021

20 What reacts with ammonia gas? hydrochloric sodium acid hydroxide Jv Jv Jv x x Jv x x key Jv = reacts X = does not react

1 marks

Answer: B

This question in 0654/22 May/June 2021

20 What reacts with ammonia gas? hydrochloric acid ~ «KX sodium hydroxide <x \ x key Jv = reacts X = does not react

1 marks

Answer: B

This question in 0654/23 May/June 2021

25 Calcium carbonate (limestone) is a base. Which uses of limestone depend on it acting as a base? 1 making lime 2 neutralising acid waste 3 stone buildings 4 treatment of soil A 1 and 2 B 2 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2021

26 Which compound is used to neutralise acidic gases? A calcium carbonate B calcium chloride C calcium phosphate D calcium sulfate

1 marks

Answer: A

This question in 0654/22 Oct/Nov 2021

20 Aqueous ammonium chloride reacts with aqueous potassium hydroxide. The equation is shown. NH4Cl + KOH  KCl + NH3 + H2O What is the role of the ammonium ion in this reaction? A an acid B a base C an electron acceptor D an electron donor

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2021

25 Which substances neutralise acids? 1 lime 2 limestone 3 calcium hydroxide A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0654/22 Feb/March 2022

25 Why do farmers add limestone to soil? A It acts as a fertiliser. B It adds nitrogen to the soil. C It decreases the pH of the soil. D It increases the pH of the soil.

1 marks

Answer: D

This question in 0654/21 May/June 2022

25 Why do farmers add limestone to soil? A It acts as a fertiliser. B It adds nitrogen to the soil. C It decreases the pH of the soil. D It increases the pH of the soil.

1 marks

Answer: D

This question in 0654/22 May/June 2022

25 Why do farmers add limestone to soil? A It acts as a fertiliser. B It adds nitrogen to the soil. C It decreases the pH of the soil. D It increases the pH of the soil.

1 marks

Answer: D

This question in 0654/23 May/June 2022

26 What is not a use of limestone? A manufacture of calcium oxide B neutralising industrial waste products C purifying water D treating acidic soil

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2022

20 Which statements about neutralisation are correct? 1 Acids and bases produce water when they neutralise each other. 2 During neutralisation, bases transfer protons to acids. 3 Neutral solutions turn universal indicator green. 4 During neutralisation, acids transfer hydroxide ions to bases. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: A

This question in 0654/21 May/June 2023

22 Which atmospheric pollutant is removed from air by lime? A ammonia B carbon monoxide C hydrocarbons D sulfur dioxide

1 marks

Answer: D

This question in 0654/21 May/June 2023

25 Which statements about limestone are correct? 1 Its main constituent is calcium oxide. 2 It can be used to manufacture lime. 3 It thermally decomposes to release carbon dioxide. 4 It is used to neutralise alkaline soils. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

1 marks

Answer: C

This question in 0654/21 May/June 2023

25 Which statements about limestone are correct? 1 It contains calcium oxide. 2 It is used to manufacture lime. 3 It neutralises acidic industrial waste products. 4 It neutralises alkaline soil. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: C

This question in 0654/22 May/June 2023

20 Solid S is added to dilute hydrochloric acid in the apparatus shown. solid S + dilute hydrochloric acid universal indicator solution The universal indicator solution shows the pH decreases. What is solid S? A zinc B zinc carbonate C zinc hydroxide D zinc oxide

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2023

20 Universal indicator solution is added to test-tubes W, X and Y. W X Y dilute aqueous aqueous hydrochloric acid sodium hydroxide sodium chloride What are the colours of the universal indicator? in test-tube W in test-tube X in test-tube Y A green red purple B purple green red C red green purple D red purple green

1 marks

Answer: D

This question in 0654/22 May/June 2024

19 What happens when an acid reacts with an alkali? A Neutralisation takes place and the temperature falls. B Neutralisation takes place and the temperature rises. C Reduction takes place and the temperature falls. D Reduction takes place and the temperature rises.

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2024

18 Which row describes chemical properties of dilute hydrochloric acid? produces a gas effect on litmus paper when added to a metal carbonate A turns red litmus blue no B turns blue litmus red no C turns red litmus blue yes D turns blue litmus red yes

1 marks

Answer: D

This question in 0654/22 Feb/March 2025

25 The word equation shown is incomplete. acid + alkali  X + water What is X? A base B carbon dioxide C hydrogen D salt

1 marks

Answer: D

This question in 0654/22 Oct/Nov 2025