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
91–100 of 156
Question 91
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.
Question 92
2 marks · Hard
Answer and see the solution →When making hydrated zinc sulfate crystals from zinc oxide and sulfuric acid, the final solution is left to cool so that crystals form. Explain, in two points, why crystallisation is used instead of evaporation to dryness to obtain hydrated salt crystals.
Question 93
5 marks · Hard
Answer and see the solution →A student prepares hydrated magnesium sulfate crystals by reacting magnesium carbonate with dilute sulfuric acid.
(a)[2 marks]Write the balanced symbol equation for the reaction between magnesium carbonate and dilute sulfuric acid.
(b)[1 mark]State the state symbols for each product.
(c)[2 marks]During the process, the solution is concentrated and then left to crystallise. Write the equation for the crystallisation step, including water of crystallisation.
Question 94
2 marks · Hard
Answer and see the solution →Describe two steps a student must carry out to obtain pure hydrated copper(II) sulfate crystals from a mixture of copper(II) oxide and dilute sulfuric acid, once the reaction has finished.
Question 95
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.
Question 96
3 marks · Easy
Answer and see the solution →A student wants to prepare pure potassium chloride crystals from potassium hydroxide solution and hydrochloric acid using titration.
(a)[1 mark]State the first step the student should carry out before adding acid.
(b)[1 mark]Describe how the student should use an indicator to find the endpoint of the reaction.
(c)[1 mark]Once the volumes have been determined, explain what the student must do to obtain pure potassium chloride crystals.
Question 97
2 marks · Easy
Answer and see the solution →Explain the role of methyl orange indicator in an acid–alkali titration to prepare potassium salts. Why does the indicator colour change at the endpoint? (2 marks)
Question 98
2 marks · Easy
Answer and see the solution →A student wants to prepare ammonium sulfate by titrating ammonium hydroxide ( ) with sulfuric acid ( ).
Write the balanced chemical equation for this reaction.
Question 99
1 mark · Easy
Answer and see the solution →State why you cannot use the 'add excess solid, then filter' method to prepare sodium salts from acid and sodium hydroxide.
Question 100
3 marks · Easy
Answer and see the solution →A student prepares pure potassium sulfate crystals from potassium hydroxide and sulfuric acid using titration.
(a)[1 mark]State the purpose of using an indicator during the titration.
(b)[2 marks]After finding the correct volumes, outline two steps the student must take to obtain pure potassium sulfate crystals.