Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
The combustion of elements in oxygen
18 practice questions
Practice questions
1–7 of 7 · Easy
Question 1
1 mark · Easy
Answer and see the solution →Name the type of reaction that takes place when an element burns in oxygen.
Question 2
3 marks · Easy
Answer and see the solution →The apparatus below is used to burn phosphorus in air:
Apparatus for burning phosphorus in air (a)[1 mark]State the name of the gas in air that phosphorus reacts with when it is burned.
(b)[1 mark]Give one observation you would make when phosphorus burns in air.
(c)[1 mark]Name the compound formed when phosphorus combusts in oxygen.
Question 3
2 marks · Easy
Answer and see the solution →During the combustion of phosphorus in air, a student measures that the water level in the bell jar rises by 44 mL. The total original air volume in the jar was 210 mL. Calculate (to the nearest whole number) the percentage of oxygen in the original air sample.
Question 4
2 marks · Easy
Answer and see the solution →Explain why it is important to leave some phosphorus unreacted at the end of the experiment when finding the percentage of oxygen in air using phosphorus.
Question 5
1 mark · Easy
Answer and see the solution →State what you would observe when magnesium burns in pure oxygen.
Question 6
3 marks · Easy
Answer and see the solution →The diagram shows an experiment in which sulfur is burned in a bell jar filled with air over a trough of water.
(a)[1 mark]Describe what you would see when sulfur burns in oxygen.
(b)[1 mark]Write a word equation for the reaction of sulfur and oxygen.
(c)[1 mark]Explain why the water level inside the bell jar rises after burning sulfur, based on the changes taking place inside the jar.
Question 7
2 marks · Easy
Answer and see the solution →A student burns phosphorus in a bell jar containing 300 cm³ of air. After the reaction, the water level inside the bell jar rises by 63 cm³. Calculate the percentage of oxygen in air, based on these results. Give your answer to the nearest whole number.