Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Gases in the Atmosphere
86 practice questions
Topics covered
Practice questions
21–30 of 86
Question 21
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 22
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 23
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 24
1 mark · Easy
Answer and see the solution →State what you would observe when magnesium burns in pure oxygen.
Question 25
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 26
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.
Question 27
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 28
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.
Question 29
1 mark · Normal
Answer and check →Which of the following best describes what happens when an element combusts in oxygen?
- A.A new compound is formed and energy is released.
- B.The element turns into a gas without reacting.
- C.The element dissolves in oxygen.
- D.No change takes place.
Question 30
2 marks · Normal
Answer and see the solution →Suggest one reason why some elements burn more brightly in pure oxygen than in air. Name an element that burns brightly in oxygen.