Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Gases in the Atmosphere
86 practice questions
Topics covered
Practice questions
1–10 of 36 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State the names and approximate percentages by volume of the two most abundant gases present in dry air.
Question 2
4 marks · Normal
Answer and see the solution →Copper can be used to determine the percentage of oxygen in air.
(a)[2 marks]Describe the main steps in the experiment using heated copper to find the percentage of oxygen in air.
(b)[1 mark]Explain why excess copper is needed in this experiment.
(c)[1 mark]Suggest one safety precaution for this practical.
Question 3
3 marks · Normal
Answer and see the solution →A sample of dry air has a total volume of 200 cm³. Calculate:
(a)[1 mark]The volume of nitrogen in the sample.
(b)[1 mark]The volume of oxygen in the sample.
(c)[1 mark]The total volume of argon and carbon dioxide in the sample, using the approximate percentages in dry air.
Question 4
3 marks · Normal
Answer and see the solution →Below are two possible sources of error in an experiment using iron filings to measure the percentage of oxygen in air:
- The experiment is stopped after only one day, before the gas syringe reading stops changing.
- Only a small amount of iron filings is added, not in excess.
For each case, explain why the result might be inaccurate and whether it would make the calculated percentage of oxygen in air higher or lower than the correct value.
Question 5
4 marks · Normal
Answer and see the solution →The table shows results from an experiment to determine the composition of air.
Estimated composition of air. Gas Estimated percentage (%) Oxygen 20 Nitrogen 75 Argon 1 Carbon dioxide 0.04 (a)[2 marks]Compare the estimated percentage of nitrogen and oxygen to their approximate true values in dry air.
(b)[2 marks]Give two possible reasons why the estimated results might differ from the true values.
Question 6
1 mark · Normal
Answer and check →Which statement best describes how the percentage of oxygen in air can be found using an experiment with wet iron filings?
- A.Measure the increase in volume of gas.
- B.Measure the decrease in volume of gas in the apparatus.
- C.Record the temperature change of the conical flask.
- D.Count how quickly the iron changes colour.
Question 7
2 marks · Normal
Answer and see the solution →Name two gases that together make up almost all of dry, unpolluted air, and state their approximate combined percentage by volume.
Question 8
4 marks · Normal
Answer and see the solution →The diagram shows an apparatus used to investigate the percentage of oxygen in air using wet iron filings.
Apparatus for determining the percentage of oxygen using iron filings. (a)[2 marks]Describe the steps taken to set up and carry out this experiment.
(b)[1 mark]Suggest how the total volume of air present in the apparatus at the beginning can be measured.
(c)[1 mark]Explain why water is used when adding the iron filings.
Question 9
2 marks · Normal
Answer and see the solution →State what is meant by a combustion reaction. Give an example of a combustion reaction involving an element.
Question 10
4 marks · Normal
Answer and see the solution →The diagram shows an experiment in which a piece of magnesium ribbon is burned in a bell jar containing air, floating on water as described.
(a)[1 mark]State what you would observe when magnesium burns in the air inside the bell jar.
(b)[1 mark]Write a word equation for the combustion of magnesium in oxygen.
(c)[2 marks]Explain why the level of water rises inside the bell jar after the reaction.