AQA GCSE Chemistry Paper 2 Higher June 2025 question paper 8462/2H

A student investigated the mass of dissolved solids in sea water.

This is the method used.

1. Weigh an empty evaporating basin.

2. Measure 10.0 cm³ of sea water sample A into the evaporating basin using a burette.

3. Heat the evaporating basin until all the water seems to have evaporated.

4. Weigh the evaporating basin and contents.

5. Calculate the mass of dissolved solids in the sample.

6. Repeat steps 1 to 5 with sea water samples B, C and D.

Why did the student use a burette rather than a measuring cylinder to measure

What was the dependent variable in this investigation?

Describe how the student could make sure all of the water had evaporated in step 3.

How did the student calculate the mass of dissolved solids in each sea water sample?

Table 1 shows the results.

Calculate the mean concentration of dissolved solids in 10.0 cm³ samples of sea water A, B, C and D.

Use Table 1 and the equation:

Suggest why sea water samples A, B, C and D contain different masses of dissolved solids.

This question is about hydrocarbon fuels.

Figure 1 represents the process used to separate hydrocarbon fuels from crude oil.

Name the process represented by Figure 1.

Changes of state take place during the process in Figure 1.

Name the change of state taking place in:

the heater

the column.

Different fuels are obtained from crude oil at the points on Figure 1 labelled A to E.

Table 2 shows the boiling point ranges of different fuels obtained from the process in Figure 1.

Which fuel is obtained at B in the column?

Use Figure 1 and Table 2.

Fuels with higher boiling point ranges contain larger molecules.

What is the order of increasing flammability of the fuels?

Use Table 2.

Tick (✓) one box.

Liquified petroleum gases are a mixture of several different hydrocarbons.

Figure 2 shows a model of one of these hydrocarbons.

Write the molecular formula of the hydrocarbon represented by the model in Figure 2

Name the hydrocarbon represented by the model in Figure 2.

Petroleum gases also contain a hydrocarbon with the formula C₃H₈

Balance the equation for the complete combustion of C₃H₈

Doors can be made from aluminium or wood.

Table 3 gives information about aluminium and wood.

Evaluate the use of aluminium and of wood for making doors.

Aluminium has an oxide coating that protects the metal from corrosion.

Explain how the oxide coating protects aluminium from corrosion.

Doors made from wood need painting to prevent rotting.

Paints are formulations made by mixing a solid pigment and a liquid.

Which statement describes the composition of a paint?

Tick (✓) one box.

The Earth’s atmosphere has changed over time.

Explain how the percentage of nitrogen changed in the Earth’s early atmosphere.

Table 4 shows the percentage (%) of carbon dioxide present in the Earth’s early atmosphere.

The percentage of carbon dioxide in the Earth’s early atmosphere changed between 4.5 billion and 3.0 billion years ago.

Give two reasons why.

Complete Figure 3.

You should:

• plot the data in Table 4

• draw a line of best fit.

Table 5 shows information about the percentage (%) of carbon dioxide and of oxygen present in the Earth’s atmosphere over time.

The percentages of carbon dioxide and of oxygen in the Earth’s atmosphere changed between 2.5 billion and 0.5 billion years ago.

Explain how.

This question is about unsaturated hydrocarbons.

Table 6 shows the boiling points of some unsaturated hydrocarbons.

Estimate the boiling point X in Table 6.

C₂H₄ reacts with water vapour (steam).

Name the compound produced when C₂H₄ reacts with water vapour.

C₄H₈ reacts with chlorine (Cl₂).

Describe the test for chlorine.

Give the result of the test.

Which is the displayed formula of the organic compound produced when C₄H₈ reacts with chlorine?

Tick (✓) one box.

Name the unsaturated hydrocarbon with the formula C₃H₆

Why does C₃H₆ tend to burn in air with a smoky flame?

C₃H₆ is a gas at room temperature and pressure.

Calculate the volume of 2.1 g of C₃H₆ at room temperature and pressure.

Give your answer in cm³.

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

Relative atomic masses (A_r): H = 1 C = 12

A student analysed three solutions, A, B and C.

Each solution contained one ionic compound.

The student added a few drops of sodium hydroxide solution to solution A.

Solution A produced a white precipitate.

Aluminium ions produce a white precipitate with a few drops of sodium hydroxide solution.

Name one other metal ion which produces a white precipitate with a few drops of sodium hydroxide solution.

Describe how the student could confirm the presence of aluminium ions in solution A

Give the result of the test.

The student tested solution B to identify the ions present.

The student did a flame test on solution B.

An orange-red flame was produced.

Write the symbol for the metal ion in solution B.

The student added dilute nitric acid followed by silver nitrate solution to solution B.

A white precipitate was produced.

Write the symbol for the non-metal ion in solution B.

The student added 1.0 mol/dm³ nitric acid to solution C.

Bubbles of gas were produced.

Describe a test on the bubbles of gas that confirms that solution C contained carbonate ions.

Give the result of the test.

The student repeated the test on solution C using 1.0 mol/dm³ ethanoic acid instead of 1.0 mol/dm³ nitric acid.

Bubbles of gas were produced more slowly using ethanoic acid.

Explain why.

Name compound A and compound B.

Compound A and compound B react to produce a condensation polymer.

Name the type of condensation polymer produced from compound A and compound B.

Name the small molecule lost when molecules of compound A and of compound B react.

Glycine is an amino acid.

Glycine can produce condensation polymers.

Name the type of condensation polymer produced when glycine polymerises.

Complete Figure 5 to show the displayed structural formula of glycine.

Which polymer is produced when different amino acids are combined in the same chain?

Tick (✓) one box.

The polymer poly(tetrafluoroethene) is produced from the monomer tetrafluoroethene (C₂F₄).

Complete the equation for the production of poly(tetrafluoroethene) from tetrafluoroethene.

Poly(tetrafluoroethene) is a thermosoftening polymer.

Some other polymers are thermosetting polymers.

Describe the structure of a thermosetting polymer.

Hydrogen peroxide decomposes into water and oxygen.

The equation for the reaction is:

A student investigated the effect of catalyst A and of catalyst B on the rate of this reaction.

Figure 6 shows the apparatus.

This is the method used.

1. Put the conical flask on the balance.

2. Add 50 cm³ of 1.5 mol/dm³ hydrogen peroxide solution to the conical flask.

3. Add 1.00 g of catalyst A to the conical flask.

4. Start a timer.

5. Record the loss in mass of the conical flask and contents every 30 seconds for 3 minutes.

6. Repeat steps 1 to 5 using catalyst B.

Explain why the conical flask and contents lost mass.

Figure 7 shows the reaction profile for the decomposition of hydrogen peroxide using:

catalyst A

catalyst B.

Explain why catalyst A and catalyst B give different rates of reaction for the decomposition of hydrogen peroxide.

Figure 8 shows the results for catalyst A.

Determine the rate of the reaction when the time was 60 seconds.

Give your answer in standard form.

Explain how the rate of decomposition of hydrogen peroxide depends on the temperature of the solution.

This question is about ammonia.

Ammonia is produced from nitrogen and hydrogen in the Haber process.

Hydrogen is produced from methane and steam.

The equation for one of the reactions in the production of hydrogen is:

The forward reaction absorbs energy from the surroundings.

Explain why a high temperature is used in this reaction.

Explain why as low a pressure as possible is used in this reaction.

A nickel catalyst is used in this reaction.

What is the effect of the nickel catalyst on the position of equilibrium?

Tick (✓) one box.

The nitrogen needed in the Haber process is obtained from air.

Calculate the approximate volume of air required to obtain 50 dm³ of nitrogen.

Figure 9 shows how ammonia is produced from nitrogen and hydrogen.

Explain how the mixture of ammonia, nitrogen and hydrogen is separated at X.

Ammonia is used to produce fertilisers.

Nitrogen is released into the air when bacteria break down fertilisers and dead plant matter.

One of the reactions during the production of hydrogen from methane (natural gas) releases carbon dioxide into the air.

The use of nitrogen to produce ammonia is more sustainable than the use of hydrogen to produce ammonia.

Give three reasons why.