Salts IGCSE

1 A method used to make copper(II) sulfate crystals is shown. 1 Place dilute sulfuric acid in a beaker.

2 Warm the acid.

3 Add copper(II) oxide until it is in excess.

4 Filter the mixture.

5 Evaporate the filtrate until crystals start to form.

6Leave the filtrate to cool. What are the purposes of step 3 and step 4?

• A

• B

• C

• D

What is the correct sequence of steps for the preparation of a pure sample of copper(II) sulfate crystals from copper(II) oxide and sulfuric acid?

• A dissolving → crystallisation → evaporation → filtration

• B dissolving → evaporation → filtration → crystallisation

• C dissolving → filtration → crystallisation → evaporation

• D dissolving → filtration → evaporation → crystallisation

Four stages in the preparation of a salt from an acid and a solid metal oxide are listed.

1 Add excess solid.

2Evaporate half the solution and leave to cool.

3 Filter to remove unwanted solid.

4 Heat the acid. In which order should the stages be carried out?

• A 1 → 3 → 4 → 2

• B 2 → 1 → 3 → 4

• C 4 → 1 → 3 → 2

• D 4 → 2 → 1 → 3

Zinc sulfate is a soluble salt and can be prepared by reacting excess zinc carbonate with dilute sulfuric acid. Which piece of equipment would not be required in the preparation of zinc sulfate crystals?

• A beaker

• B condenser

• C evaporating dish

• D filter funnel

Four steps to prepare a salt from an excess of a solid base and an acid are listed.

1 crystallisation

2 evaporation

3 filtration

4 neutralisation

In which order are the steps carried out?

• A 2 →

• B 3 →

• C 4 →

• D 4 →

Which method is used to make the salt copper sulfate?

• dilute acid + alkali

• dilute acid + carbonate

• dilute acid + metal

• dilute acid + non-metal oxide

Which two processes are involved in the preparation of magnesium sulfate from dilute sulfuric acid and an excess of magnesium oxide?

• neutralisation and filtration

• neutralisation and oxidation

• thermal decomposition and filtration

• thermal decomposition and oxidation

Hydrochloric acid is used to clean metals. The acid reacts with the oxide layer on the surface of the metal, forming a salt and water. Which word describes the metal oxide?

• A alloy

• B base

• C element

• D indicator

Which statement is not correct?

• A When a base reacts with an ammonium salt, ammonia is given off.

• When an acid reacts with a base, neutralisation takes place.

• When an acid reacts with a carbonate, carbon dioxide is given off.

• When the acidity of a solution increases, the pH increases.

Which reaction is not characteristic of an acid?

• It dissolves magnesium oxide.

• It produces ammonia from ammonium compounds

• It produces carbon dioxide from a carbonate.

• It produces hydrogen from zinc metal.