AQA GCSE Chemistry Paper 2 Higher June 2024 question paper 8462/2H

A student investigated an aqueous solution of a salt.

The student identified that the salt solution contained only sodium ions and chloride ions.

Describe a test to identify sodium ions.

Give the result of the test.

Test for sodium ions

Describe a test to identify chloride ions.

Give the result of the test.

Test for chloride ions

The student determined the concentration of sodium chloride in the salt solution.

This is the method used.

1. Weigh an empty evaporating dish.

2. Add 25.0 cm³ of the salt solution into the evaporating dish.

3. Heat the evaporating dish and contents.

4. Weigh the evaporating dish and contents.

5. Repeat steps 3 to 4 until there is no further change in mass.

6. Repeat steps 1 to 5 three more times.

Why did the student heat the evaporating dish and contents until the mass did not change?

How did the student calculate the mass of solid sodium chloride remaining after steps 1 to 5?

Tick (✓) one box.

The student calculated the concentration of sodium chloride in the salt solution.

Table 1 shows the results.

The percentage by mass of sodium ions in sodium chloride is 39.3%.

Calculate the mean concentration of sodium ions in the salt solution.

This question is about ammonia and nitric acid.

In the Haber process ammonia is produced from nitrogen and hydrogen.

Figure 1 represents the Haber process.

Pipe P links the condenser to the reactor.

Why is the condenser linked to the reactor?

Use Figure 1.

Which metal is used as a catalyst in this reaction?

Nitric acid is produced by reacting ammonia with oxygen.

The word equation for the production of nitric acid is:

ammonia + oxygen → water + nitric acid

Platinum is a catalyst in this reaction.

Describe the test for oxygen gas.

Give the result if oxygen gas is present.

Figure 2 represents the reaction profile of the catalysed reaction between ammonia and oxygen.

Complete the reaction profile for the catalysed reaction in Figure 2.

You should:

label the activation energy

label the reactants and products, using the names of the reactants and products.

How would Figure 2 be different if no catalyst was used?

Tick (✓) one box.

Ammonia and nitric acid react to produce the salt, ammonium nitrate.

Ammonium ions and nitrate ions both contain nitrogen.

Suggest one use of ammonium nitrate.

This question is about water.

Hydrogen gas reacts with oxygen gas to produce water.

Water is decomposed into hydrogen gas and oxygen gas using electricity.

Which two words describe the reaction between hydrogen gas and oxygen gas?

Tick (✓) two boxes.

Water molecules break down into hydrogen ions and hydroxide ions.

The equation for the reaction is:

Which sentence describes this reaction at equilibrium?

Tick (✓) one box.

Water collected from rivers is used in the home for drinking and flushing toilets.

Water used in the home must be potable.

Potable water is safe to drink.

Waste water produced after use in the home is called sewage.

Figure 3 shows how water is collected from rivers and returned to rivers after use.

Explain what happens to water in Process A and in Process B in Figure 3.

Do not refer to use of water in the home.

A student investigated an orange dye (A) using paper chromatography.

Figure 4 shows the results of Experiment 1 and Experiment 2 using orange dye A.

Explain why the yellow dye and red dye travel different distances in Experiment 1.

Refer to forces of attraction between the dyes and the chromatography paper in your answer.

The student used the same type of chromatography paper in Experiment 1 and in Experiment 2.

Explain why the yellow dye is in different positions in Experiment 1 and in Experiment 2.

Use Figure 4.

Figure 4 is repeated below.

Figure 4 shows the results of Experiment 1 and Experiment 2 using orange dye A.

The student investigated a different orange dye (B).

Figure 5 shows the results of Experiment 3 using orange dye B.

Compare the purity of the orange dyes A and B.

Give reasons for your answer.

Use Figure 4 and Figure 5.

The student calculated that the R_f value of the orange dye in the experiment shown in Figure 5 was 0.48

Calculate the distance moved by the solvent front when the orange dye had moved 5.4 cm.

Why is the R_f value of a dye not affected by how far the solvent front is allowed to travel?

Another type of chromatography is called gas chromatography.

Gas chromatography is an instrumental method of chemical analysis.

Scientists tested the orange dyes using gas chromatography.

Suggest two advantages of using the instrumental method of gas chromatography rather than paper chromatography.

This question is about burning fuels in central heating boilers.

In the future, gas central heating boilers may burn hydrogen rather than natural gas.

Table 2 shows information about these fuels when 1 dm³ of the fuel is burned in a central heating boiler.

Explain how oxides of nitrogen are produced when burning fuels.

Explain one positive impact on the environment of burning hydrogen rather than natural gas as a fuel.

Use Table 2.

Explain one negative impact on the environment of burning hydrogen rather than natural gas as a fuel.

Use Table 2.

Air is 20% oxygen.

Calculate the volume of air needed to provide enough oxygen to react with 3.50 dm³ of hydrogen gas.

The equation for the reaction is

Central heating boilers can also burn kerosene.

Kerosene is produced from crude oil in a fractionating column using fractional distillation.

In the first step, crude oil is heated and hydrocarbon vapours are formed.

Explain how kerosene is produced from these hydrocarbon vapours.

This question is about materials used to make bicycles.

Figure 6 shows a bicycle.

Table 3 shows information about two materials used to make bicycle frames.

Evaluate the use of aluminium alloy and of bamboo for making bicycle frames.

Use Table 3.

Explain why aluminium alloy bicycle frames do not need protection from corrosion.

Bicycle chains are made from an alloy of iron.

Bicycle chains rust without protection.

Paint is not used to protect bicycle chains from rusting.

Suggest how bicycle chains can be protected from rusting.

Bicycle frames can also be made from a composite of carbon fibres embedded in a polymer resin.

What description is given in this composite to:

the carbon fibre component

the polymer resin component?

This question is about sulfuric acid.

Sulfuric acid contains sulfate ions.

Describe the test for the presence of sulfate ions in sulfuric acid.

Give the result of the test.

One stage in the industrial production of sulfuric acid is the reaction of sulfur dioxide with oxygen to produce sulfur trioxide.

This reversible reaction reaches dynamic equilibrium.

Figure 7 shows the percentage yield of sulfur trioxide in this reaction at different temperatures.

Which statement about the forward reaction is correct?

Use Figure 7.

Tick (✓) one box.

The equation for the reaction is:

Explain why the percentage yield of sulfur trioxide in this reaction is greater if the pressure is higher.

In industry, the reaction is done at 450 °C and atmospheric pressure.

Under these conditions the yield of sulfur trioxide is 86%.

Suggest two reasons why a higher pressure is not used.

This reaction uses a catalyst to increase the rate of the reaction.

The catalyst is a metal oxide.

Which is the most likely metal in the metal oxide catalyst?

Use the periodic table.

Tick (✓) one box.

This question is about monomers and polymers.

Compound A has an alkene functional group and an ester functional group.

Figure 8 represents a molecule of compound A.

Draw a circle around the alkene functional group on Figure 8.

Describe what will be seen when compound A is shaken with bromine water.

Figure 9 is a repeat of Figure 8.

Draw a circle around the ester functional group on Figure 9.

Compound A has the formula C₄H₆O₂

Compound A is flammable.

Write a balanced equation for the complete combustion of compound A.

Many molecules of compound A join together to form polymer B.

Complete the displayed formula equation which represents this reaction.

What type of polymer is polymer B ?

Tick (✓) one box.

Polymer B is a polymer which melts when heated.

What word is used to describe polymers which melt when heated?

Explain why some polymers do not melt when heated.

A student investigated the rate of the reaction between zinc and sulfuric acid.

The equation for the reaction is

Figure 10 shows the apparatus.

This is the method used.

1. Pour 50 cm³ of sulfuric acid into the conical flask.

2. Add excess zinc to the conical flask.

3. Insert the stopper and start a timer.

4. Measure the volume of hydrogen collected in the 50 cm³ measuring cylinder every 20 seconds for 180 seconds.

Explain why the volume of hydrogen collected in the 50 cm³ measuring cylinder is less than the volume of hydrogen produced.

Figure 11 shows the volumes of hydrogen collected in the 50 cm³ measuring cylinder after 40 seconds and after 100 seconds.

Determine the number of moles of hydrogen collected between 40 seconds and 100 seconds.

The volume of one mole of any gas at room temperature and pressure is 24 dm³.

A different student investigated how the concentration of sulfuric acid affected the rate of the reaction.

The student did a different experiment using sulfuric acid of

The student calculated the number of moles of hydrogen collected after every 20 seconds.

Figure 12 shows the results.

Determine the rate of reaction at 45 seconds.

You should draw a tangent on Figure 12.

Give your answer in standard form.

Figure 13 shows the results for 0.40 mol/dm³ sulfuric acid.

The student repeated the experiment using 0.20 mol/dm³ sulfuric acid instead of 0.40 mol/dm³ sulfuric acid.

Excess zinc was used in each experiment.

Sketch a line on Figure 13 to show the results you would expect.

Explain how increasing the temperature would affect the rate of reaction between zinc and sulfuric acid.