Chemistry 0620 · IGCSE
Air quality and climate
100 practice questions on Air quality and climate, with worked solutions and instant marking.
Which statement gives a disadvantage of sulfur dioxide?
Feb/March 2016
Which pollutant gas may be formed as a consequence of the incomplete combustion of octane, $\text{C}_8\text{H}_{18}$?
Feb/March 2016
The diagram shows an experiment that is used to determine the percentage of oxygen in $150\,\text{cm}^3$ of polluted air. The apparatus is then left for one week. After this period, the gas volume in the measuring cylinder is $122\,\text{cm}^3$. What is the percentage of oxygen, to the nearest whole number, in the polluted air?
Feb/March 2017
A setup for determining the percentage of oxygen in $150\,\text{cm}^3$ of polluted air is shown. The apparatus is then left for one week. After this period, the gas volume in the measuring cylinder is $122\,\text{cm}^3$. What percentage of oxygen is present in the polluted air, correct to the nearest whole number?
Feb/March 2017
Which gas is absent from clean air?
Feb/March 2018
During the decomposition of vegetation, which pollutant gas is released?
Feb/March 2018
Which processes do not release carbon dioxide?
Feb/March 2018
What pollutant gas is released during the decomposition of vegetation?
Feb/March 2018
State the name of the hydrocarbon found in the highest concentration in natural gas.
Feb/March 2018
Which row that shows an air pollutant and its main source is incorrect?
Feb/March 2019
Methane and carbon dioxide are both greenhouse gases. Which row shows one source of methane and one source of carbon dioxide?
Feb/March 2019
Which process takes carbon dioxide out of the Earth’s atmosphere?
Feb/March 2019
Sulfur dioxide, carbon monoxide and oxides of nitrogen are common gaseous pollutants present in the atmosphere. Which pollutants play a part in acid rain formation?
Feb/March 2020
Which process does not release a greenhouse gas into the atmosphere?
Feb/March 2020
Sulfur dioxide, carbon monoxide and oxides of nitrogen are widespread gaseous pollutants in the air. Which of these pollutants cause acid rain?
Feb/March 2020
In petrol engines of cars, oxides of nitrogen such as NO and NO$_2$ are produced. The car’s catalytic converter removes them from the exhaust gases by means of reactions. Which row shows how oxides of nitrogen are produced in a petrol engine, and a reaction taking place in the catalytic converter?
Feb/March 2020
Which pollutants lead to the erosion of buildings and statues? 1 carbon monoxide gas 2 oxides of nitrogen gases 3 sulfur dioxide gas
Feb/March 2021
Which process does not result in carbon dioxide being produced?
Feb/March 2021
Certain combustion reactions release pollutant gases. Which of these reactions produce a pollutant gas that is absent from clean air?
Feb/March 2023
Certain combustion reactions give off pollutant gases. Which of the reactions form a pollutant gas that is absent from clean air?
Feb/March 2023
This question concerns gases present in clean, dry air and gases present in polluted air.
Feb/March 2023
In what way do carbon dioxide and methane lead to global warming?
Feb/March 2024
Which statement concerning the composition of clean, dry air is correct?
Feb/March 2025
Which row shows a source of methane and one harmful effect of methane?
Feb/March 2025
A test to determine the percentage of oxygen in $150\,\text{cm}^3$ of polluted air is illustrated. The apparatus is then left for one week. After this period, the volume of gas in the measuring cylinder is $122\,\text{cm}^3$. What is the percentage of oxygen, to the nearest whole number, in the polluted air?
Feb/March 2025
A previously unknown planet has been found, and the gases in its atmosphere have been examined. The table gives the proportions of the gases in its atmosphere. Which gases are found in the planet’s atmosphere at a greater percentage than in Earth’s atmosphere?
May/June 2016
Which air pollutant has no effect on respiration?
May/June 2016
A newly found planet has had its atmosphere analysed. The table gives the composition of its atmosphere: carbon dioxide $4\%$, nitrogen $72\%$, oxygen $24\%$. Which gases occur in the atmosphere of the planet at a greater percentage than they do in the Earth’s atmosphere?
May/June 2016
Sulfur dioxide, carbon monoxide and oxides of nitrogen are widespread gaseous pollutants present in the air. Which pollutants are responsible for acid rain?
May/June 2016
A newly found planet has had its atmosphere analysed. The table gives the make-up of its atmosphere. carbon dioxide: $4\%$ nitrogen: $72\%$ oxygen: $24\%$ Which gases occur in the planet’s atmosphere at a greater percentage than in Earth’s atmosphere?
May/June 2016
When petrol is burnt inside a car engine, the substances below may be produced. Which substance is chiefly responsible for acid rain?
May/June 2016
A newly discovered planet has had its atmosphere analysed. The table gives the makeup of this atmosphere. Which gases occur in the planet’s atmosphere at a greater percentage than in Earth’s atmosphere?
May/June 2016
A new planet has been found, and scientists have analysed its atmosphere. The table gives the make-up of this atmosphere. Which gases occur in the planet’s atmosphere at a higher percentage than in Earth’s atmosphere?
May/June 2016
The gases released from a car’s engine include oxides of nitrogen. In what way are these oxides formed?
May/June 2016
A newly found planet has had its atmosphere analysed. The table gives the composition of this atmosphere. Which gases are present in the planet’s atmosphere at a greater percentage than in Earth’s atmosphere?
May/June 2016
Clean dry air is made up mostly of nitrogen and oxygen.
May/June 2016
Which gas has no colour and is poisonous?
May/June 2017
During which process is carbon dioxide not produced?
May/June 2017
Which pollutant gas cannot be formed by burning fossil fuels (coal, petroleum and natural gas)?
May/June 2017
Polluted air contains oxides of nitrogen. Which statement about oxides of nitrogen is true?
May/June 2017
The carbon cycle involves combustion, photosynthesis and respiration. Which row shows the effect of each process on the amount of carbon dioxide in the atmosphere?
May/June 2017
Which chemical reaction reduces pollution in the air?
May/June 2017
The carbon cycle explains how carbon dioxide gas is transferred into and out of the atmosphere. Which row shows how carbon dioxide moves in each process?
May/June 2017
Petrol burns in a car engine, producing waste gases that exit through the car exhaust. One of these waste gases is an oxide of nitrogen. Which statement explains how this oxide of nitrogen is formed?
May/June 2017
Carbon is found in Group IV of the Periodic Table, and it combines with oxygen to produce carbon dioxide.
May/June 2017
Dry air is sent over heated copper until every bit of the oxygen has reacted. At the end of the reaction, the gas volume is $120\,\text{cm}^3$. What was the initial volume of dry air?
May/June 2018
Which process is not associated with the emission of a greenhouse gas?
May/June 2018
Carbon dioxide and methane are both greenhouse gases that help to cause climate change. Which statement describes how greenhouse gases contribute to climate change?
May/June 2018
Which of the following statements about the carbon cycle are correct?
May/June 2018
Which of the following statements about the carbon cycle are correct?
May/June 2018
Which of the following statements about the carbon cycle are correct?
May/June 2018
The table gives the percentage by volume of each gas found in the exhaust from a petrol engine fitted with a catalytic converter.
May/June 2018
Four causes of air pollution are given below. 1 burning fossil fuels containing sulfur 2 nitrogen reacting with oxygen in car engines 3 incomplete combustion of carbon fuels 4 adding lead compounds to petrol Which of these causes produce acid rain?
May/June 2019
Which statement gives a disadvantage of sulfur dioxide?
May/June 2019
The gases below contaminate the atmosphere. Which of them are responsible for acid rain?
May/June 2019
Which statement gives a disadvantage of sulfur dioxide?
May/June 2019
Which of the following statements about acid rain is incorrect?
May/June 2019
Which statement gives a disadvantage of sulfur dioxide?
May/June 2019
Car engines produce oxides of nitrogen, which cause air pollution. Catalytic converters are fitted to car exhausts in order to reduce this pollution. What is done to the oxides of nitrogen in the catalytic converter?
May/June 2019
The carbon cycle is illustrated. Which row gives the descriptions of processes X, Y and Z?
May/June 2019
Car exhaust gases include oxides of nitrogen. How do these oxides of nitrogen form?
May/June 2019
Some processes in the carbon cycle are illustrated below. 1. glucose $+$ oxygen $\rightarrow$ carbon dioxide $+$ water 2. carbon dioxide $+$ water $\rightarrow$ glucose $+$ oxygen 3. methane $+$ oxygen $\rightarrow$ carbon dioxide $+$ water What are the names given to these processes?
May/June 2019
In the exhausts of cars, catalytic converters turn polluting gases into gases that do not pollute. Which statements concerning oxides of nitrogen and car engines are correct?
May/June 2019
Which row is correct about the carbon cycle?
May/June 2019
State one source from which sulfur dioxide enters the air.
May/June 2019
Oxides of nitrogen are air pollutants.
May/June 2019
Which two gases together account for about $99\%$ of clean, dry air?
May/June 2021
Which gas is a pollutant in the air that leads to acid rain?
May/June 2021
Which process takes carbon dioxide out of the atmosphere?
May/June 2021
Which process in the carbon cycle removes carbon dioxide from the atmosphere?
May/June 2021
Which gas is an air pollutant and causes acid rain?
May/June 2021
This question concerns air and gases.
May/June 2021
This question concerns air.
May/June 2021
Which process gives rise to methane?
May/June 2022
Which row shows a substance found in clean air and a substance that acts as an air pollutant?
May/June 2022
Carbon dioxide and methane are both greenhouse gases. Which activity results in the release of both of these gases?
May/June 2022
Which of the following statements about carbon monoxide is correct?
May/June 2022
Which processes result in carbon dioxide being produced?
May/June 2022
Which processes add to the amount of carbon dioxide in the air?
May/June 2022
Below is a list of substances. aluminium oxide carbon dioxide chlorine diamond ethanol glucose iron(III) oxide limestone nitrogen oxygen Use the substances in the list to answer the questions. Each substance can be chosen once, used more than once, or left unused.
May/June 2022
Some details about gas X are given below. • It does not occur in clean, dry air. • It does not cause respiratory problems. • It contributes to global warming. What is X?
May/June 2023
Which compounds both cause acid rain?
May/June 2023
The three air pollutants, X, Y and Z, are outlined below. X is a poisonous gas produced when an alkane undergoes incomplete combustion. Y is produced when vegetation decomposes and it adds to global warming. Z leads to breathing difficulties and acid rain. What are the identities of X, Y and Z?
May/June 2023
Which compounds are both involved in causing acid rain?
May/June 2023
An air sample made up of only four gases is analysed. Which row gives the percentage composition of the air sample?
May/June 2024
Name two harmful impacts of particulates in the air.
May/June 2024
Four gases present in air are listed below. Which of them cause global warming directly when their concentrations increase?
May/June 2024
Which strategies help to reduce the formation of acid rain?
May/June 2024
Car engines that run on gasoline as a fuel generate oxides of nitrogen. The oxides of nitrogen are taken out of the exhaust gases. Which statements about how oxides of nitrogen are formed or removed are correct?
May/June 2024
The gases below are listed. ammonia helium hydrogen carbon dioxide carbon monoxide chlorine methane nitrogen dioxide propene sulfur dioxide Answer the questions that follow about these gases. Each gas can be used once, more than once, or not at all.
May/June 2024
In the experiment illustrated, $100\,\text{cm}^3$ of clean, dry air is sent to and fro through a tube packed with heated copper until the air volume no longer falls. The entire gas sample is then forced into a single syringe. What reading is obtained on this gas syringe?
May/June 2025
Sulfur dioxide, carbon monoxide and oxides of nitrogen are gaseous pollutants present in the air. Which of these pollutants cause acid rain?
May/June 2025
Which gas makes up over 30% of clean, dry air?
May/June 2025
The reaction equation for carbon dioxide and water, with chlorophyll and sunlight present, is displayed below. $\text{carbon dioxide} + \text{water} \xrightarrow[\text{sunlight}]{\text{chlorophyll}} \text{glucose} + \text{oxygen}$ Which process is represented by this equation?
May/June 2025
Which statements help to explain why a larger amount of carbon dioxide or methane in the atmosphere leads to global warming?
May/June 2025
Car exhaust gases contain oxides of nitrogen. By what process are these oxides of nitrogen produced?
May/June 2025
Gases that cause acid rain are formed in car engines. A catalytic converter can be used to remove these gases. Which equation represents the removal of one of these gases by a catalytic converter?
May/June 2025
Which gas plays a part in raising global warming?
May/June 2025
Which statement explains how greenhouse gases cause global warming to increase?
May/June 2025
Which statement about carbon dioxide and methane is correct?
Oct/Nov 2016