Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Showing that air contains about one-fifth oxygen
19 practice questions
Practice questions
1–8 of 8 · Easy
Question 1
1 mark · Easy
Answer and see the solution →State the approximate percentage by volume of oxygen in dry air.
Question 2
3 marks · Easy
Answer and see the solution →Describe how an experiment using phosphorus could be used to show the percentage of oxygen in air.
(a)[1 mark]State what happens to the phosphorus when it reacts in a jar of air.
(b)[1 mark]Describe how the volume of air changes during the experiment.
(c)[1 mark]Explain how the result of this change can be used to find the percentage of oxygen in air.
Question 3
2 marks · Easy
Answer and see the solution →A 250 cm³ sample of dry, unpolluted air is analysed.
Calculate the approximate volume of argon in the sample. Give your answer to 2 decimal places.
Question 4
2 marks · Easy
Answer and see the solution →Explain why it is important to use excess copper in the experiment to determine the percentage of oxygen in air using copper.
Question 5
3 marks · Easy
Answer and see the solution →The table below shows the major gases in dry, unpolluted air.
Main gases in dry air Gas Percentage by volume (%) Nitrogen Oxygen Argon Carbon dioxide Question 6
1 mark · Easy
Answer and see the solution →Name one substance (other than a metal) that can be used to remove oxygen from air in an experiment to determine its percentage.
Question 7
3 marks · Easy
Answer and see the solution →Answer the following about the gases in dry, unpolluted air.
(a)[1 mark]Name the most abundant gas in dry air.
(b)[1 mark]State the gas present in the smallest amount from the main four gases.
(c)[1 mark]Give the percentage by volume of carbon dioxide in dry air, to two decimal places.
Question 8
2 marks · Easy
Answer and see the solution →In an experiment to find the percentage of oxygen in air using iron filings, the total air volume at the start is 180 cm³. At the end, the volume is 143 cm³. Calculate the percentage of oxygen in the air. Give your answer to the nearest whole number.