Making soluble salts

Lithium reacts with chlorine to produce lithium chloride.

Figure 10 shows models of chlorine and of lithium chloride.

Draw one line from each substance to the type of bonding in the substance.

Lithium chloride can also be produced by reacting lithium carbonate with an acid.

Which acid reacts with lithium carbonate to produce lithium chloride?

Tick () one box.

Hydrochloric acid

Nitric acid

Sulfuric acid

What type of substance is lithium chloride?

Tick () one box.

Acid

Alkali

Salt

Figure 11 shows the electrolysis of lithium chloride solution.

Lithium chloride solution contains Li⁺ ions and Cl⁻ ions.

Chloride ions move to the positive electrode to produce chlorine.

Explain why chloride ions move to the positive electrode.

Hydrogen gas and chlorine gas are produced during the electrolysis of lithium chloride solution.

Draw one line from each gas to the result of the test for that gas.

Why is hydrogen gas produced at the negative electrode?

Tick () one box.

Hydrogen is less reactive than lithium.

Hydrogen has the same reactivity as lithium.

Hydrogen is more reactive than lithium.

Hydrogen reacts with chlorine to produce hydrogen chloride. A hydrogen atom has 1 electron in the outer shell.

A chlorine atom has 7 electrons in the outer shell.

Complete the dot and cross diagram for a hydrogen chloride molecule.

Use the symbols O and X to represent electrons.

This question is about copper and copper compounds.

A teacher demonstrated the reaction of copper with silver nitrate.

Figure 16 shows the apparatus:

at the start

after a few minutes.

The word equation for the reaction is:

solution solution

What type of reaction happens between copper and silver nitrate?

Tick () one box.

Combustion

Displacement

Neutralisation

Give two observations that can be made when copper reacts with silver nitrate solution.

Use Figure 16 and the word equation.

Copper reacted with silver nitrate solution.

The teacher then added copper to nickel nitrate solution.

Copper did not react with nickel nitrate solution.

Write the order of reactivity for copper, nickel and silver.

A student reacted solid copper oxide with nitric acid to produce a solution of copper nitrate.

This is the method used.

1. Add 25 cm³ of nitric acid to a beaker.

2. Warm the nitric acid.

3. Add solid copper oxide to the nitric acid.

4. Stir the mixture.

5. Repeat steps 3 and 4 until solid copper oxide is in excess.

Give one safety precaution the student should use.

The nitric acid was warmed in step 2 of the method.

Suggest how the reaction was affected by warming the nitric acid.

After the reaction finished, the beaker contained a mixture of solid copper oxide and copper nitrate solution.

Describe a method to obtain pure, dry copper nitrate crystals from the mixture.

This question is about acids and alkalis.

Universal indicator is used to measure the pH of solutions.

Figure 16 shows the colours of universal indicator at different pH values.

A student added universal indicator to nitric acid in a beaker.

The student added drops of potassium hydroxide solution to the nitric acid until pH 7 was reached.

The student could not be sure that the pH of the mixture was 7

Give one reason why.

Use Figure 16.

Name a piece of equipment that could be used to give a more accurate measurement of pH.

Name the type of reaction when potassium hydroxide solution reacts with nitric acid.

The formula of nitric acid is HNO₃

Calculate the relative formula mass (M_r) of nitric acid.

Relative atomic masses (A_r): H = 1 N = 14 O = 16

Potassium hydroxide is an alkali.

Which ion do all alkalis contain?

Tick () one box.

H⁺ K⁺ O²⁻ OH⁻

The concentration of the solution of potassium hydroxide was 5.6 g/dm³.

Calculate the mass of potassium hydroxide in 5 cm³ of the solution.

1 dm³ = 1000 cm³

Excess hydrochloric acid in the stomach can cause pain. The excess hydrochloric acid can be neutralised by a calcium carbonate tablet.

A student investigated how the pH changed when a calcium carbonate tablet was added to hydrochloric acid.

This is the method used.

1. Add 10 cm³ of hydrochloric acid to a beaker.

2. Measure the pH of the hydrochloric acid using an indicator.

3. Add a calcium carbonate tablet to the hydrochloric acid.

4. Time for 3 minutes.

5. Measure the pH of the mixture using an indicator.

Which two of the following pieces of equipment are needed in this method?

Tick (✓) two boxes.

Measuring cylinder

Newtonmeter

Ruler

Stop clock

Thermometer

Name an indicator used to measure pH.

Name a piece of equipment that gives a more accurate pH value than an indicator.

The word equation for the reaction is:

calcium carbonate + hydrochloric acid calcium chloride + water + carbon dioxide

Why is fizzing seen during the reaction?

Give one safety precaution the student should have taken.

What is the pH of a neutral solution?

Tick (✓) one box.

1 4 7 10

A student reacted hydrochloric acid with excess calcium carbonate.

A solution of calcium chloride was produced.

Figure 5 shows the method used to produce calcium chloride crystals from the reaction mixture.

Describe the method shown in Figure 5 to produce calcium chloride crystals from the reaction mixture.

Include the equipment used.

This question is about acids and salts.

Nitric acid is a strong acid.

A solution of nitric acid can be dilute.

Explain how nitric acid can be both strong and dilute.

The pH value of a solution of nitric acid increases by 1.

How does the hydrogen ion concentration of the solution change?

Tick (✓) one box.

Decreases by a factor of 10

Decreases by a factor of 100

Increases by a factor of 10

Increases by a factor of 100

Question 8 continues in the next page

A student reacted nitric acid with excess calcium carbonate.

The word equation for the reaction is:

calcium carbonate + nitric acid calcium nitrate + water + carbon dioxide

This is the method used.

1. Measure 100 cm³ of nitric acid into a beaker.

2. Add calcium carbonate powder to the nitric acid.

3. Stir the mixture.

4. Repeat steps 2 and 3 until the calcium carbonate is in excess.

5. Filter the mixture.

Describe the additional steps that should be included in the method to determine the mass of calcium carbonate that reacted.

The formula of nitric acid is HNO₃

Which expression gives the percentage (%) by mass of oxygen in HNO₃?

Relative atomic mass (A_r): O = 16

Relative formula mass (M_r): HNO₃ = 63

Tick (✓) one box.

What is the formula of calcium nitrate?

Use the periodic table.

Tick (✓) one box.

CaNO₃

Ca(NO₃)₂

Ca₂NO₃

Ca₂(NO₃)₃

Question 8 continues in the next page

Magnesium chloride is a salt.

Calculate the number of magnesium ions in 47.5 g of magnesium chloride (MgCl₂).

Relative atomic masses (A_r): Mg = 24 Cl = 35.5

Avogadro constant = 6.02 × 10²³ per mole

This question is about acids and alkalis.

Which ion is produced by all acids in aqueous solution?

Tick (✓) one box.

Cl⁻ H⁺ Na⁺ OH⁻

The pH scale is a measure of the acidity or alkalinity of a solution.

What is used to measure the pH of a solution?

Tick (✓) one box.

Iodine solution

Limewater

Universal indicator

Give one safety precaution used when measuring the pH of an acid.

Sodium hydroxide solution reacts with sulfuric acid to produce a salt and one other product.

Which salt is produced when sodium hydroxide solution reacts with sulfuric acid?

Tick (✓) one box.

Sodium chloride

Sodium nitrate

Sodium sulfate

What is the other product when sodium hydroxide solution reacts with sulfuric acid?

Tick (✓) one box.

Oxygen

Sodium

Water

Draw one line from each solution to the pH of that solution.

What is the type of reaction when sodium hydroxide solution reacts with sulfuric acid?

Tick (✓) one box.

Combustion

Decomposition

Neutralisation

Copper oxide reacts with sulfuric acid to produce copper sulfate.

What type of substance is copper oxide?

Tick (✓) one box.

Acid

Alkali

Base

Salt

A student produced a pure, dry sample of copper sulfate crystals.

This is the first part of the method.

1. Measure 100 cm³ of sulfuric acid into a beaker.

2. Gently warm the sulfuric acid.

3. Add 1.0 g of copper oxide powder to the sulfuric acid.

4. Stir the mixture.

5. Repeat steps 3 and 4 until the copper oxide is in excess.

6. Filter the mixture.

Describe the additional steps needed to produce a pure, dry sample of copper sulfate crystals.

The student added excess copper oxide.

Describe the steps that the student could include in the method to find the mass of copper oxide that reacted.

The student found that 2.4 g of copper oxide had reacted.

Copper oxide (CuO) is an ionic compound.

Calculate the total number of ions in 2.4 g of copper oxide.

Relative atomic masses (A_r): Cu = 63.5 O = 16

The Avogadro constant = 6.02 × 10²³ per mole

A student wanted to make blue copper sulfate crystals from green copper carbonate powder and sulfuric acid.

Figure 13 shows the method the student used.

The student obtained a mixture of coloured powders not blue crystals.

Describe how the method could be improved so that blue copper sulfate crystals are produced.

A student wanted to make blue copper sulfate crystals from green copper carbonate powder and sulfuric acid.

Figure 2 shows the method the student used.

The student obtained a mixture of coloured powders not blue crystals.

Describe how the method could be improved so that blue copper sulfate crystals are produced.

This question is about copper sulfate.

The formula of copper sulfate is CuSO₄

Table 5 shows information about the atoms in copper sulfate.

Complete Table 5.

Copper oxide and sulfuric acid react to produce copper sulfate and water.

Complete the word equation for this reaction.

What type of substance is copper oxide?

Tick (✓) one box.

A student planned to make blue copper sulfate crystals.

This is the method the student used.

1. Add 25 cm³ of dilute sulfuric acid to a conical flask.

2. Gently warm the dilute sulfuric acid.

3. Add 2 g of black copper oxide to the dilute sulfuric acid.

4. Stir the mixture.

5. Evaporate some of the water from the mixture using an electric heater.

6. Leave the mixture to cool.

Not all the copper oxide reacted. The student did not remove the excess copper oxide.

What would the product look like after step 6?

Tick (✓) one box.

The student should have filtered the mixture after step 4.

Draw a diagram of the apparatus the student could use.

You should label:

• the pieces of equipment used

• where the excess copper oxide collects.

What equipment should the student use to measure:

• 2 g of copper oxide

• 25 cm³ of dilute sulfuric acid?

Draw one line from each measurement to the most suitable piece of equipment.

1 g of copper sulfate is dissolved in water to make 25 cm³ of copper sulfate solution.

Calculate the concentration of the copper sulfate solution in g/dm³

A student planned to make copper sulfate crystals from excess copper oxide and dilute sulfuric acid.

The equation for the reaction is:

Why is it necessary to add excess copper oxide?

This is the method used.

1. Add 25 cm³ of dilute sulfuric acid to a conical flask.

2. Gently warm the dilute sulfuric acid.

3. Add excess copper oxide to the dilute sulfuric acid.

4. Stir the mixture.

5. Heat to evaporate all the water from the mixture.

Suggest two improvements to the method.

Explain why each improvement is needed.

The student used:

• 2 g of copper oxide (in excess)

• 25 cm³ of a solution of dilute sulfuric acid with a concentration of 49 g/dm³

Determine by how many moles the copper oxide (CuO) was in excess.

Relative atomic masses (A_r): Cu = 63.5 O = 16

Relative formula mass (M_r) of sulfuric acid = 98

A teacher demonstrated the temperature change when hydrochloric acid is added to sodium hydroxide.

This is the method used.

1. Add 25.0 cm³ of sodium hydroxide solution to a polystyrene cup.

2. Measure the temperature of the sodium hydroxide solution.

3. Add 25.0 cm³ of hydrochloric acid to the sodium hydroxide solution.

4. Stir the solution.

5. Measure the maximum temperature of the solution.

Draw one line from each measurement to the most suitable piece of equipment to use to make the measurement.

The teacher did the experiment four times.

Table 1 shows the teacher’s results.

Calculate the mean maximum temperature rise.

Do not use the anomalous result in your calculation.

How could the accuracy of the experiment be improved?

Tick one box.

The reaction between hydrochloric acid and sodium hydroxide is a neutralisation reaction.

The reaction produces a salt and one other product.

Complete the word equation for the reaction.

Universal indicator is used to measure the pH of solutions.

Hydrochloric acid is pH 1

Sodium hydroxide is pH 13

Draw one line from the pH to the colour of universal indicator in a solution with that pH.

When a metal carbonate reacts with an acid, a salt, carbon dioxide and water are produced.

Describe how you would test for carbon dioxide gas.

Give the result of the test.

Describe how to make pure dry crystals of magnesium chloride from magnesium carbonate and a dilute acid.

In your method you should name the apparatus and reagents you plan to use.

When a metal carbonate reacts with an acid, a salt, carbon dioxide and water are produced.

Describe how you would test for carbon dioxide gas.

Give the result of the test.

Describe how to make pure dry crystals of magnesium chloride from magnesium carbonate and a dilute acid.

In your method you should name the apparatus and reagents you plan to use.