Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Acids, Bases and Salt Preparations
156 practice questions
Topics covered
- Reactions of acids18 practice questions
- Reacting acids with bases19 practice questions
- Reacting acids with carbonates19 practice questions
- Salt preparations19 practice questions
- Making soluble salts (except sodium, potassium and ammonium salts)19 practice questions
- Making sodium, potassium and ammonium salts18 practice questions
- Making insoluble salts19 practice questions
- Theories of acids and bases19 practice questions
Practice questions
81–90 of 156
Question 81
1 mark · Easy
Answer and see the solution →State why crystallisation is used instead of evaporation to dryness when preparing hydrated salts.
Question 82
3 marks · Easy
Answer and see the solution →Hydrated magnesium sulfate crystals can be prepared using magnesium and dilute sulfuric acid.
(a)[1 mark]Write the balanced symbol equation for the reaction.
(b)[1 mark]State the gaseous product formed.
(c)[1 mark]Write the equation for the crystallisation reaction to form hydrated magnesium sulfate.
Question 83
2 marks · Easy
Answer and see the solution →A student uses 50 cm³ of dilute sulfuric acid in a beaker to prepare a soluble salt. Give the two reasons for heating the acid gently in this experiment.
Question 84
2 marks · Normal
Answer and see the solution →Describe how you would prepare pure, hydrated zinc sulfate crystals starting from zinc oxide and dilute sulfuric acid.
Question 85
4 marks · Normal
Answer and see the solution →(a)[1 mark]State what would be produced if copper(II) sulfate solution was heated to dryness instead of being left to crystallise.
(b)[2 marks]Explain why crystallisation is used to obtain hydrated copper(II) sulfate crystals rather than evaporating to dryness.
(c)[1 mark]Describe a test to confirm if the product is a hydrated salt.
Question 86
3 marks · Normal
Answer and see the solution →Write a balanced chemical equation for the reaction between magnesium carbonate and dilute sulfuric acid to form magnesium sulfate. State the products and their physical states.
Question 87
3 marks · Normal
Answer and see the solution →A student tries to make a pure sample of hydrated magnesium sulfate crystals using magnesium and dilute sulfuric acid.
Explain, in steps, what the student must do to obtain pure crystals and why each step is necessary.
Question 88
4 marks · Normal
Answer and see the solution →A student attempts to make hydrated nickel(II) sulfate crystals. Step Observation Add nickel(II) oxide to warm dilute sulfuric acid Black solid gradually disappears More nickel(II) oxide added Some solid remains at the bottom Filter the mixture Green solution collected Heat solution until some water evaporates Residue remains green Cool the solution Green crystals form (a)[1 mark]Explain why nickel(II) oxide is added in excess (step 2).
(b)[1 mark]Describe the purpose of step 3 (filtration).
(c)[1 mark]Explain why the solution is cooled after heating (step 5).
(d)[1 mark]Suggest a reason why it would be incorrect to heat the green solution to dryness in step 4.
Question 89
1 mark · Normal
Answer and check →Which of the following is the correct balanced equation for the reaction of copper(II) oxide with dilute sulfuric acid to make copper(II) sulfate?
- A.\ce{CuO(s) + H2SO4(aq) -> CuSO4(aq) + H2O(l)}
- B.\ce{CuO(aq) + H2SO4(s) -> CuSO4(l) + H2O(aq)}
- C.\ce{CuSO4(s) + H2SO4(aq) -> CuO(aq) + H2O(l)}
- D.\ce{Cu(s) + H2SO4(aq) -> CuSO4(aq) + H2(g)}
Question 90
2 marks · Normal
Answer and see the solution →Give two safety precautions you would take when preparing hydrated iron(II) sulfate crystals using dilute sulfuric acid and iron(II) oxide.