Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Making soluble salts (except sodium, potassium and ammonium salts)
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
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 2
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 3
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 4
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 5
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 6
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 7
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.
Question 8
4 marks · Normal
Answer and see the solution →(a)[1 mark]Define the term 'hydrated salt'.
(b)[2 marks]Explain, with reference to water of crystallisation, how heating a hydrated salt to dryness changes its formula.
(c)[1 mark]How can you tell if a sample of copper(II) sulfate is hydrated or anhydrous? State what you would observe on heating.