Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Showing that air contains about one-fifth oxygen
19 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →Name the two most abundant gases in dry, unpolluted air. State their approximate percentage composition by volume for each gas.
Question 2
5 marks · Hard
Answer and see the solution →The diagram below shows apparatus used to investigate the amount of oxygen in air using heated copper.
Apparatus for measuring oxygen in air with heated copper. Describe and explain how this experiment is carried out to determine the percentage of oxygen in air.
(a)[2 marks]State what change you would expect to see in the copper during the experiment, and explain your answer.
(b)[3 marks]Describe how you would use the readings from the gas syringes to calculate the percentage of oxygen in air. Include the calculation in your answer.
Question 3
2 marks · Hard
Answer and see the solution →Argon and carbon dioxide are both present in dry, unpolluted air. Which is present in a larger amount? Give an approximate percentage for both gases.