Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Gases in the Atmosphere
86 practice questions
Topics covered
Practice questions
11–20 of 36 · Normal
Question 11
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 12
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.
Question 13
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 14
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 15
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 16
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 17
2 marks · Normal
Answer and see the solution →State whether the following oxides are acidic or basic:
(a)[1 mark]Sodium oxide (Na2O)
(b)[1 mark]Carbon dioxide (CO2)
Question 18
4 marks · Normal
Answer and see the solution →The table below shows some oxides and whether they are formed from metals or non-metals.
(a)[0 marks]Some examples of oxides Oxide Element type Calcium oxide Metal Sulfur dioxide Non-metal Magnesium oxide Metal Carbon dioxide Non-metal (b)[2 marks]Complete the table by writing whether each oxide is acidic or basic.
(c)[2 marks]Explain why magnesium oxide and sulfur dioxide have different acid-base properties.
Question 19
3 marks · Normal
Answer and see the solution →Copper(II) oxide is formed by heating copper in oxygen.
Copper(II) oxide reacts with hydrochloric acid to form copper(II) chloride and water.
Explain, with reasons, why copper(II) oxide is classified as a basic oxide. Include in your answer what type of element forms this oxide, and what is observed when it is added to hydrochloric acid.
Question 20
4 marks · Normal
Answer and see the solution →Below is a table of some oxides and whether each produces an acidic, basic, or neutral solution when dissolved in water. Complete the table.
(a)[4 marks]Properties of some oxides in water Oxide Solution formed in water (acidic, basic or neutral) Iron(III) oxide Silicon dioxide Sodium oxide Nitrogen monoxide