AQA GCSE Chemistry Paper 1 Higher November 2021 question paper 8462/1H

This question is about carbon and its compounds.

Fullerenes are molecules of carbon atoms. The first fullerene to be discovered was Buckminsterfullerene (C₆₀).

What shape is a Buckminsterfullerene molecule?

Give one use of a fullerene.

Propanone is a compound of carbon, hydrogen and oxygen. Figure 1 shows the dot and cross diagram for a propanone molecule.

Complete Figure 2 to show a propanone molecule. Use a line to represent each single bond. Use Figure 1.

Figure 2

Determine the molecular formula of propanone. Use Figure 1.

Propanone is a liquid with a low boiling point. Why does propanone have a low boiling point? Tick (✓) one box.

Figure 3 represents the structure of graphite.

Explain why graphite is:

• a good electrical conductor

• soft and slippery.

You should answer in terms of structure and bonding.

This question is about atomic structure and the periodic table. Gallium (Ga) is an element that has two isotopes.

Give the meaning of ‘isotopes’. You should answer in terms of subatomic particles.

Table 1 shows the mass numbers and percentage abundances of the isotopes of gallium.

Calculate the relative atomic mass (A_r) of gallium. Give your answer to 1 decimal place.

Gallium (Ga) is in Group 3 of the modern periodic table.

Give the numbers of electrons and neutrons in an atom of the isotope⁶⁹₃₁Ga

What is the most likely formula of a gallium ion? Tick (✓) one box.

Gallium was discovered six years after Mendeleev published his periodic table. Give two reasons why the discovery of gallium helped Mendeleev’s periodic table to become accepted.

This question is about the extraction of metals.

Element R is extracted from its oxide by reduction with hydrogen. The equation for the reaction is:

The sum of the relative formula masses (M_r) of the reactants (3 H₂ + RO₃) is 150 Calculate the relative atomic mass (A_r) of R. Relative atomic masses (A_r): H = 1 O = 16

Identify element R. You should use:

• your answer to question 03.1

• the periodic table.

Identity of R =

Carbon is used to extract tin (Sn) from tin oxide (SnO₂). The equation for the reaction is:

Calculate the percentage atom economy for extracting tin in this reaction. Relative atomic masses (A_r): C = 12 O = 16 Sn = 119

Tungsten (W) is a metal. Tungsten is extracted from tungsten oxide (WO₃). All other solid products from the extraction method must be separated from the tungsten. Table 2 shows information about three possible methods to extract tungsten from tungsten oxide.

Evaluate the three possible methods for extracting tungsten from tungsten oxide.

This question is about Group 1 elements.

Give two observations you could make when a small piece of potassium is added to water.

Complete the equation for the reaction of potassium with water. You should balance the equation.

Explain why the reactivity of elements changes going down Group 1.

Sodium reacts with oxygen to produce the ionic compound sodium oxide. Oxygen is a Group 6 element.

Draw a dot and cross diagram to show what happens when atoms of sodium and oxygen react to produce sodium oxide. Diagram

Why is oxygen described as being reduced in the reaction between sodium and oxygen?

Explain why sodium oxide has a high melting point.

This question is about salts.

Name the salt produced by the neutralisation of hydrochloric acid with potassium hydroxide.

Write an ionic equation for the neutralisation of hydrochloric acid with potassium hydroxide.

Soluble salts can be produced by reacting dilute hydrochloric acid with an insoluble solid. Copper, copper carbonate and copper oxide are insoluble solids. Which of these insoluble solids can be used to make a copper salt by reacting the solid with dilute hydrochloric acid? Tick (✓) one box.

A student makes crystals of magnesium sulfate. This is the method used.

1. Add sulfuric acid to a beaker.

2. Warm the sulfuric acid.

3. Add a spatula of magnesium oxide to the beaker.

4. Stir the mixture.

5. Repeat steps 3 and 4 until there is magnesium oxide remaining in the beaker.

6. Filter the mixture.

7. Evaporate the filtrate gently until crystals start to form.

8. Leave the solution to finish crystallising.

Give one reason for:

• step 2

• step 5

• step 6.

How should the filtrate be evaporated gently in step 7 ?

Iron chloride is produced by heating iron in chlorine gas. The equation for the reaction is:

Calculate the volume of chlorine needed to react with 14 g of iron. You should calculate:

• the number of moles of iron used

• the number of moles of chlorine that react with 14 g of iron

• the volume of chlorine needed.

Relative atomic mass (A_r): Fe = 56 The volume of 1 mole of gas = 24 dm³

This question is about metals.

Table 3 shows information about four substances.

Which substance could be a metal? Tick (✓) one box.

Explain why alloys are harder than pure metals.

A student wants to compare the reactivity of an unknown metal, Q, with that of zinc. Both metals are more reactive than silver. The student is provided with:

• silver nitrate solution

• metal Q powder

• zinc powder

• a thermometer

• normal laboratory equipment.

No other chemicals are available. Describe a method the student could use to compare the reactivity of metal Q with that of zinc. Your method should give valid results.

This question is about chemical reactions and electricity.

Electrolysis and chemical cells both involve chemical reactions and electricity. Explain the difference between the processes in electrolysis and in a chemical cell.

A teacher demonstrates the electrolysis of molten lead bromide. Bromine is produced at the positive electrode. Complete the half equation for the production of bromine. You should balance the half equation.

Two aqueous salt solutions are electrolysed using inert electrodes. Complete Table 4 to show the product at each electrode.

Some students investigated the electrolysis of copper nitrate solution using inert electrodes. Figure 4 shows the apparatus.

The students investigated how the mass of copper produced at the negative electrode varied with:

• time

• current.

This is the method used.

1. Weigh the negative electrode.

2. Set up the apparatus shown in Figure 4.

3. Adjust the power supply until the ammeter shows a current of 0.3 A

4. Switch off the power supply after 5 minutes.

5. Rinse the negative electrode with water and allow to dry.

6. Reweigh the negative electrode.

7. Repeat steps 1 to 6 for different times.

8. Repeat steps 1 to 7 at different currents.

Some of the copper produced did not stick to the negative electrode but fell to the bottom of the beaker. Suggest how the students could find the total mass of copper produced.

The students plotted their results on a graph. Figure 5 shows the graph.

A student correctly concluded that the total mass of copper produced is directly proportional both to the time and to the current.

How do the results in Figure 5 support the conclusion that the total mass of copper produced is directly proportional to the time?

How do the results in Figure 5 support the conclusion that the total mass of copper produced is directly proportional to the current? Use data from Figure 5 in your answer.

Copper nitrate solution is blue. Suggest why the blue colour of the copper nitrate solution fades during the electrolysis.

Determine the number of atoms of copper produced when copper nitrate solution is electrolysed for 20 minutes at a current of 0.6 A Give your answer to 3 significant figures. Use Figure 5. Relative atomic mass (A_r): Cu = 63.5 The Avogadro constant = 6.02 10²³ per mole

This question is about the reaction between hydrogen sulfide (H₂S) and oxygen. The equation for the reaction is:

What does H₂O(g) represent?

Calculate the volume of oxygen required to react with 50 cm³ of hydrogen sulfide.

Figure 6 shows part of the reaction profile for the reaction. The reaction is exothermic. Complete Figure 6. You should:

• complete the profile line

• label the activation energy

• label the overall energy change.

Figure 7 shows the displayed formula equation for the reaction of hydrogen sulfide with oxygen.

Figure 7

Table 5 shows some of the bond energies.

In the reaction the energy released forming new bonds is 1034 kJ/mol greater than the energy needed to break existing bonds. Calculate the bond energy X for the bond. Use Figure 7 and Table 5.

This question is about acids. Hydrogen chloride and ethanoic acid both dissolve in water. All hydrogen chloride molecules ionise in water. Approximately 1% of ethanoic acid molecules ionise in water.

A solution is made by dissolving 1 g of hydrogen chloride in 1 dm³ of water. Which is the correct description of this solution? Tick (✓) one box.

Which solution would have the lowest pH? Tick (✓) one box.

A student investigated the concentration of a solution of sodium hydroxide by titration with a 0.0480 mol/dm³ ethanedioic acid solution. This is the method used.

1. Measure 25.0 cm³ of the sodium hydroxide solution into a conical flask using a 25.0 cm³ pipette.

2. Add two drops of indicator to the sodium hydroxide solution.

3. Fill a burette with the 0.0480 mol/dm³ ethanedioic acid solution to the 0.00 cm³ mark.

4. Add the ethanedioic acid solution to the sodium hydroxide solution until the indicator changes colour.

5. Read the burette to find the volume of the ethanedioic acid solution used.

Suggest two improvements to the method that would increase the accuracy of the result.

Ethanedioic acid is a solid at room temperature. Calculate the mass of ethanedioic acid (H₂C₂O₄) needed to make 250 cm³ of a solution with concentration 0.0480 mol/dm³ Relative formula mass (M_r): H₂C₂O₄ = 90

The student found that 25.0 cm³ of the sodium hydroxide solution was neutralised by 15.00 cm³ of the 0.0480 mol/dm³ ethanedioic acid solution. The equation for the reaction is:

Calculate the concentration of the sodium hydroxide solution in mol/dm³