Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Gases in the Atmosphere
86 practice questions
Topics covered
Practice questions
31–40 of 86
Question 31
4 marks · Normal
Answer and see the solution →Sulfur burns in oxygen to make a new substance.
(a)[1 mark]Describe what you would see when sulfur is burned in oxygen.
(b)[1 mark]Write a balanced chemical equation for the reaction between sulfur and oxygen.
(c)[1 mark]Name the product formed.
(d)[1 mark]Briefly explain why burning sulfur in oxygen is a combustion reaction.
Question 32
3 marks · Normal
Answer and see the solution →When magnesium burns in oxygen, it forms magnesium oxide. Student A burns 1.2 g of magnesium in excess oxygen. The equation is:
Calculate the mass of magnesium oxide formed. (Relative atomic masses: Mg = 24, O = 16)
Question 33
3 marks · Normal
Answer and see the solution →Sodium burns with a bright yellow flame when heated in oxygen. Explain, with reference to the reaction, why the flame is brighter and the reaction is faster when sodium is heated in pure oxygen, compared to heating it in air.
Question 34
4 marks · Normal
Answer and see the solution →The diagram below shows a scientist burning a piece of magnesium in a bell jar filled with air. The bell jar is placed over a trough of water. After ignition, the magnesium burns in oxygen to form magnesium oxide.
Burning magnesium in a bell jar over water. Measured water volumes used to fill the bell jar to marked levels before and after reaction. Water level Volume / cm³ Initial 695 Final 830 After burning, the white magnesium oxide forms and dissolves in the water. The levels of water inside the bell jar before and after combustion are shown in the table.
(a)[1 mark]State one observation you would see when magnesium reacts with oxygen in this experiment.
(b)[1 mark]Calculate the volume of oxygen that was used up during the reaction. Show your working.
(c)[1 mark]Given that the total volume of air in the bell jar at the start was 695 cm³, calculate the percentage of oxygen in the air based on your answer to (b). Show your answer to two significant figures.
(d)[1 mark]Explain why there might still be some magnesium left after the experiment.
Question 35
2 marks · Hard
Answer and see the solution →Explain why a strip of iron wool burns more vigorously in pure oxygen than in air.
Question 36
5 marks · Hard
Answer and see the solution →Sodium and magnesium both burn in oxygen, forming new compounds. The reactions are more vigorous in pure oxygen than in air.
(a)[1 mark]Write a balanced chemical equation for the reaction of sodium with oxygen.
(b)[2 marks]Describe what you would observe when magnesium burns in pure oxygen.
(c)[2 marks]Explain, using ideas about the percentage of oxygen in air, why sodium and magnesium burn more vigorously in pure oxygen than in air.
Question 37
2 marks · Hard
Answer and see the solution →Describe what is meant by a combustion reaction, and give one example of such a reaction involving an element.
Question 38
1 mark · Easy
Answer and see the solution →State whether sodium oxide is an acidic oxide or a basic oxide.
Question 39
3 marks · Easy
Answer and see the solution →The table shows information about two oxides.
(a)[1 mark]Name the type of element (metal or non-metal) that forms magnesium oxide.
(b)[1 mark]State whether magnesium oxide reacts with acids, with alkalis, or with both.
(c)[1 mark]Give the general property (acidic or basic) of non-metal oxides.
Question 40
2 marks · Easy
Answer and see the solution →Explain why carbon dioxide is classed as an acidic oxide. Give a reason for your answer.