Air quality and climate — Paper 2 · IGCSE Chemistry (9-1) 0971

28 Dry air is passed over hot copper until all the oxygen has reacted. dry air copper heat The volume of gas at the end of the reaction is 120 cm3. What is the starting volume of dry air? A 132 cm3 B 152 cm3 C 180 cm3 D 570 cm3

1 marks

Answer: B

This question in 0971/21 May/June 2018

32 Which statements about the carbon cycle are correct? 1 Carbon dioxide is added to the atmosphere by respiration. 2 Carbon dioxide is added to the atmosphere by combustion of coal. 3 Carbon dioxide is removed from the atmosphere by photosynthesis. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 0971/21 May/June 2018

29 Which statements about sulfur dioxide pollution are correct? 1 It increases the pH of rivers. 2 It damages limestone buildings. 3 It causes respiratory problems. A 1 only B 2 only C 1 and 3 D 2 and 3

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2018

30 Argon is a noble gas used to fill light bulbs. What is the approximate percentage of argon in air? A 1% B 20% C 79% D 99%

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2018

32 In the carbon cycle, which two processes add carbon dioxide to the atmosphere? A combustion and carbonate formation B combustion and photosynthesis C combustion and respiration D respiration and photosynthesis

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2018

34 What is not a use of lime? A It is used as a bleach in the manufacture of wood pulp. B It is used to desulfurise flue gases. C It is used to neutralise acidic industrial waste. D It is used to treat acidic soil.

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2018

29 Oxides of nitrogen are formed in car engines and are a source of air pollution. To decrease this pollution, catalytic converters are fitted to car exhausts. What happens to the oxides of nitrogen in the catalytic converter? A combustion B cracking C oxidation D reduction

1 marks

Answer: D

This question in 0971/21 May/June 2019

32 The carbon cycle is shown. atmospheric carbon dioxide X respiration decomposition Y Z green plants dead organic matter death and excretion animals Which row describes processes X, Y and Z? X Y Z A respiration combustion photosynthesis B respiration photosynthesis combustion C photosynthesis combustion respiration D photosynthesis respiration combustion

1 marks

Answer: C

This question in 0971/21 May/June 2019

33 The diagram represents an outline of the carbon cycle. carbon dioxide photosynthesis in the atmosphere Y respiration X plants animals power stations death and excretion organic waste fossil fuels Which processes are X and Y? X Y A combustion respiration B decomposition respiration C photosynthesis combustion D respiration combustion

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2019

30 Which process removes carbon dioxide from the atmosphere? A combustion B decomposition C photosynthesis D respiration

1 marks

Answer: C

This question in 0971/21 May/June 2020

30 Three processes in the carbon cycle are shown. 1 Methane reacts with oxygen producing carbon dioxide and water. 2 Carbon dioxide and water are absorbed and used by plants to make oxygen. 3 Oxygen is used by living things to release energy. Which processes have taken place? 1 2 3 A combustion photosynthesis respiration B combustion respiration photosynthesis C photosynthesis combustion respiration D respiration photosynthesis combustion

1 marks

Answer: A

This question in 0971/22 May/June 2020

33 A student suggests three uses of calcium carbonate (limestone). 1 manufacture of cement 2 manufacture of iron 3 treating alkaline soils Which suggestions are correct? A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: A

This question in 0971/22 May/June 2020

33 Part of the carbon cycle is shown. combustion Q R glucose CO2 plant CH4 P What are processes P, Q and R? P Q R A decomposition respiration photosynthesis B respiration photosynthesis decomposition C respiration decomposition photosynthesis D photosynthesis respiration decomposition

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2020

30 Which process removes carbon dioxide from the atmosphere? A combustion of fossil fuels B fermentation C photosynthesis D respiration

1 marks

Answer: C

This question in 0971/21 May/June 2021

21 Burning fossil fuels releases sulfur dioxide which leads to acid rain. Which ion in the rain water causes it to be acidic? A H+ B OH– C O2– D SO4 2–

1 marks

Answer: A

This question in 0971/22 May/June 2021

32 Which process in the carbon cycle is responsible for removing carbon dioxide from the atmosphere? A combustion B decomposition C photosynthesis D respiration

1 marks

Answer: C

This question in 0971/22 May/June 2021

33 The equations represent two reactions, P and Q, of lime (calcium oxide). P CaO + SiO2  CaSiO3 Q CaO + SO2  CaSO3 In which processes do the reactions occur? P Q A extraction of iron extraction of iron B extraction of iron flue gas desulfurisation C flue gas desulfurisation extraction of iron D flue gas desulfurisation flue gas desulfurisation

1 marks

Answer: B

This question in 0971/22 May/June 2021

30 Which process does not produce a greenhouse gas? A acid rain on limestone buildings B combustion of wood C digestion in cows D zinc reacting with sulfuric acid

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2021

33 Which statements about sulfur dioxide are correct? 1 Sulfur dioxide decolourises acidified potassium manganate(VII). 2 Sulfur dioxide forms when acids react with carbonates. 3 Sulfur dioxide is used as a bleach. 4 Sulfur dioxide is used to treat acidic soil. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: A

This question in 0971/21 May/June 2022

32 Which processes produce carbon dioxide? 1 respiration 2 photosynthesis 3 fermentation 4 combustion of hydrogen 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 2022

29 Which substance in polluted air damages stonework and kills trees? A carbon dioxide B carbon monoxide C lead compounds D sulfur dioxide

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2022

30 What is the equation for photosynthesis? A CO2 + 3H2 → CH3OH + H2O B 6CO2 + 6H2O → C6H12O6 + 6O2 C C6H12O6 → 2C2H5OH + 2CO2 D C6H12O6 + 6O2 → 6CO2 + 6H2O

1 marks

Answer: B

This question in 0971/21 May/June 2023

31 Which statement describes how the C–H bonds in methane gas in the atmosphere contribute to global warming? A They absorb thermal energy from the Sun and emit some of this energy into space. B They absorb thermal energy from the Sun and emit all of this energy towards the Earth. C They absorb thermal energy from the Earth and emit all of this energy towards the Earth. D They absorb thermal energy from the Earth and emit some of this energy towards the Earth.

1 marks

Answer: D

This question in 0971/21 May/June 2023

25 Which compounds both contribute to acid rain? A carbon monoxide and carbon dioxide B carbon monoxide and oxides of nitrogen C oxides of nitrogen and sulfur dioxide D sulfur dioxide and carbon dioxide

1 marks

Answer: C

This question in 0971/22 May/June 2023

31 Carbon dioxide acts as a greenhouse gas by interacting with a particular type of energy that radiates from the Earth’s surface into the atmosphere. Which type of energy is involved and what happens when this energy interacts with carbon dioxide molecules? type of what happens energy involved A thermal carbon dioxide molecules increase the Earth’s energy loss to space B thermal carbon dioxide molecules absorb the energy C light carbon dioxide molecules increase the Earth’s energy loss to space D light carbon dioxide molecules absorb the energy

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2023

32 Oxides of nitrogen, such as NO and NO2, are formed in the petrol engines of cars. They are removed from the exhaust gases by reactions in the car’s catalytic converter. Which row describes how oxides of nitrogen are formed in a petrol engine and a reaction that happens in the catalytic converter? a reaction that happens how oxides of nitrogen are formed in the catalytic converter A by the reaction between 2NO + 2CO  N2 + 2CO2 nitrogen and oxygen from the air B by the reaction between 2NO + 2H2  N2 + 2H2O nitrogen and oxygen from the air C by the reaction between nitrogen 2NO + 2CO  N2 + 2CO2 compounds in petrol and oxygen from the air D by the reaction between nitrogen 2NO + 2H2  N2 + 2H2O compounds in petrol and oxygen from the air

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2023

35 Oxides of nitrogen are produced by car engines. In a catalytic converter oxides of nitrogen are removed by reacting them with compound X. Which row describes the type of reaction oxides of nitrogen undergo and identifies compound X? type of reaction compound X A oxidation carbon dioxide B oxidation carbon monoxide C reduction carbon dioxide D reduction carbon monoxide

1 marks

Answer: D

This question in 0971/21 May/June 2024

31 Which oxide is used to neutralise acidic gases in flue gas desulfurisation? A calcium oxide B carbon dioxide C nitrogen oxide D sulfur dioxide

1 marks

Answer: A

This question in 0971/22 May/June 2024

32 Some information about three gases, P, Q and R, is listed. • Gas P forms when magnesium reacts with dilute hydrochloric acid. • Gas Q makes up 78% of the air. • Gas R forms when gas P reacts with gas Q. What is gas R? A ammonia B methane C nitrogen dioxide D water vapour

1 marks

Answer: A

This question in 0971/22 May/June 2024

27 Which row identifies two greenhouse gases and three processes by which they contribute to global warming? two greenhouse gases three processes A carbon dioxide and methane absorption, creation and reflection of thermal energy B carbon dioxide and oxygen absorption, creation and reflection of thermal energy C carbon dioxide and methane absorption, emission and reflection of thermal energy D methane and oxygen absorption, emission and reflection of thermal energy

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2024

30 Gases which cause acid rain form in car engines. These gases can be removed using a catalytic converter. Which equation represents the removal of one of these gases using a catalytic converter? A CO2 + C  2CO B 2CO + 2NO  2CO2 + N2 C N2 + 2O2  2NO2 D 2NO + O2  2NO2

1 marks

Answer: B

This question in 0971/22 May/June 2025

31 Which statements about carbon dioxide are correct? 1 Carbon dioxide absorbs thermal energy from the Earth. 2 Carbon dioxide increases the thermal energy loss to space. 3 The level of carbon dioxide in the atmosphere has increased due to the burning of fossil fuels. 4 Carbon dioxide is the only gas that causes global warming. A 1 and 2 B 1 and 3 C 2 and 3 D 2 and 4

1 marks

Answer: B

This question in 0971/22 May/June 2025

31 Which statement about oxides of nitrogen is correct? A They are made in car engines by the incomplete combustion of gasoline at a high temperature. B They are made in car engines when nitrogen in gasoline reacts with oxygen in air at a high temperature. C They are removed from car exhausts by catalytic converters and form nitrogen and sulfur dioxide. D They are removed from car exhausts when they react with carbon monoxide in catalytic converters.

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2025

33 The diagram represents two processes, X and Y, and their effect, Z, in increasing global warming. emission of thermal energy X Y Z from the Earth Which row identifies X, Y and Z? X Y Z A absorption of emission of reduced thermal thermal energy by thermal energy energy loss to space greenhouse gases to the Earth B emission of emission of reduced thermal thermal energy by thermal energy energy loss to space greenhouse gases to space C absorption of emission of increased thermal thermal energy by thermal energy energy loss to space greenhouse gases to the Earth D emission of emission of increased thermal thermal energy by thermal energy energy loss to space greenhouse gases to space

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2025