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
31–40 of 66 · Easy
Question 31
2 marks · Easy
Answer and see the solution →A solution containing 10 g of sodium chloride is left to crystallise. If the maximum solubility of sodium chloride in water at room temperature is 36 g per 100 g of water, calculate whether all the salt will dissolve in 20 g of water.
Question 32
1 mark · Easy
Answer and see the solution →Write a balanced chemical equation for the reaction between magnesium and dilute sulfuric acid to form magnesium sulfate.
Question 33
3 marks · Easy
Answer and see the solution →A student is making hydrated iron(II) sulfate crystals using dilute sulfuric acid and iron(II) oxide.
(a)[1 mark]State why the student adds excess iron(II) oxide to the acid.
(b)[1 mark]Describe how the student removes the unreacted iron(II) oxide from the mixture.
(c)[1 mark]Explain what the student should do next to obtain hydrated iron(II) sulfate crystals.
Question 34
2 marks · Easy
Answer and see the solution →A student tries to obtain hydrated magnesium sulfate crystals by evaporating the solution to dryness instead of crystallising it.
Explain, in two points, why this method does not produce hydrated crystals.
Question 35
2 marks · Easy
Answer and see the solution →Explain, using balanced equations, why hydrogen gas is produced when magnesium reacts with dilute sulfuric acid to make magnesium sulfate.
Question 36
3 marks · Easy
Answer and see the solution →The table shows observations during a student's preparation of hydrated copper(II) sulfate from copper(II) oxide and dilute sulfuric acid.
Step Observation Add excess copper(II) oxide to warm acid Black solid remains Filter the mixture Blue solution collected Heat solution until nearly saturated Blue crystals begin to form when cooled (a)[1 mark]What does the black solid remaining in the beaker show about the reaction?
(b)[1 mark]Why is the solution filtered at this stage?
(c)[1 mark]Explain how the appearance of blue crystals shows the solution is nearly saturated.
Question 37
1 mark · Easy
Answer and see the solution →State why crystallisation is used instead of evaporation to dryness when preparing hydrated salts.
Question 38
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 39
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 40
1 mark · Easy
Answer and see the solution →Explain why the titration method must be used when preparing sodium salts from an acid and an alkali.