Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Salt preparations
19 practice questions
Practice questions
11–19 of 19
Question 11
1 mark · Normal
Answer and check →Which method is most suitable for preparing a pure, dry sample of potassium nitrate in the laboratory?
- A.Reacting dilute nitric acid with potassium hydroxide and crystallising from solution
- B.Reacting potassium carbonate with dilute hydrochloric acid and filtering the mixture
- C.Mixing potassium nitrate with water and filtering out the excess solid
- D.Reacting potassium nitrate with silver nitrate and collecting the precipitate
Question 12
4 marks · Normal
Answer and see the solution →Iron(II) sulfate can be made by reacting an acid with a suitable base in the laboratory.
(a)Name two reactants you could use to prepare iron(II) sulfate.
(b)[1 mark]Write the balanced chemical equation for this reaction.
(c)[3 marks]Describe the steps you would take to obtain pure iron(II) sulfate crystals from the reaction mixture.
Question 13
4 marks · Normal
Answer and see the solution →A student wants to prepare a pure, dry sample of barium sulfate in the laboratory. Barium sulfate is insoluble in water.
(a)[1 mark]Name two suitable soluble solutions that could be mixed to prepare barium sulfate.
(b)[2 marks]Describe the steps the student should follow to obtain pure, dry barium sulfate from the mixture after the reaction is complete.
(c)[1 mark]Explain why filtration is necessary in this method.
Question 14
3 marks · Normal
Answer and see the solution →Copper(II) sulfate can be made by adding excess copper(II) oxide to dilute sulfuric acid.
(a)[1 mark]Explain why an excess of copper(II) oxide is added during the preparation.
(b)[2 marks]Describe what the student should do after all the acid has reacted, to obtain dry copper(II) sulfate crystals.
Question 15
4 marks · Normal
Answer and see the solution →The table below shows the solubility of different ionic compounds in water:
Solubility of Various Ionic Compounds in Water Compound Solubility Potassium nitrate Soluble Sodium chloride Soluble Calcium sulfate Almost insoluble Lead(II) chloride Insoluble Ammonium carbonate Soluble Copper(II) hydroxide Insoluble (a)[1 mark]Name one compound from the table that is insoluble in water.
(b)[1 mark]State the general rule for the solubility of nitrates.
(c)[2 marks]Identify a compound from the table that would be suitable for making a salt by precipitation, and explain your choice.
Question 16
2 marks · Normal
Answer and see the solution →State the solubility rules for (i) all chlorides, and (ii) all hydroxides, in water.
Question 17
2 marks · Hard
Answer and see the solution →State two exceptions to the general solubility of chlorides in water. For each exception, name the insoluble chloride.
Question 18
5 marks · Hard
Answer and see the solution →You are asked to prepare a pure, dry sample of magnesium sulfate in the laboratory using insoluble magnesium carbonate and dilute sulfuric acid.
(a)[2 marks]Explain why magnesium carbonate and sulfuric acid can be used to prepare magnesium sulfate by this method.
(b)[3 marks]Describe the steps you would take to obtain a pure, dry sample of magnesium sulfate from these reactants.
Question 19
2 marks · Hard
Answer and see the solution →State the general solubility rules for carbonates and hydroxides of common metals in water.