AQA GCSE Chemistry Paper 1 Higher June 2025 question paper 8462/1H

This question is about elements in the periodic table.

Describe where the non-metallic elements are found in the periodic table.

Gallium (Ga) is a metallic element in Group 3.

Which of these properties of gallium is not typical of most metals?

Tick () one box.

A sodium atom can be represented as²³₁₁Na

Complete Figure 1 to show the electronic structure of a sodium atom.

Mendeleev created an early periodic table.

Mendeleev placed most of the elements in order of atomic weight.

Tellurium and iodine were not placed in order of atomic weight.

Why did Mendeleev not place tellurium and iodine in order of atomic weight?

Argon is an element in Group 0 of the periodic table.

Explain why argon is unreactive.

An element X consists of two isotopes.

What is meant by ‘isotopes’?

Answer in terms of subatomic particles.

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

Which is the closest estimate to the relative atomic mass of X ?

Tick () one box.

This question is about structure and bonding.

Calcium sulfide is an ionic compound.

Figure 2 represents the structure of calcium sulfide.

Determine the empirical formula of calcium sulfide.

Calcium is in Group 2 of the periodic table.

Sulfur is in Group 6 of the periodic table.

Describe what happens when a calcium atom reacts with a sulfur atom.

Answer in terms of electrons and ions.

Figure 3 shows the structure of graphite.

Describe the structure and bonding of graphite.

Substances that consist of small molecules do not conduct electricity.

Give one reason why.

Methane consists of small molecules.

Poly(ethene) is a polymer.

Why does poly(ethene) have a higher melting point than methane?

Tick () one box.

This question is about metals and metal oxides.

Tin (Sn) is extracted from tin oxide using carbon.

The equation for the reaction is:

Which substance is reduced in this reaction?

Give one reason for your answer.

Answer in terms of oxygen.

Substance reduced

Why can carbon be used to extract tin from tin oxide?

Cadmium (Cd) can be extracted by the reaction of cadmium oxide with carbon.

The equation for the reaction is:

Calculate the percentage atom economy for the production of cadmium in this reaction.

Relative atomic masses (A_r): C = 12 Cd = 112

Relative formula mass (M_r): CdO = 128

Tungsten is a transition metal.

Potassium is a Group 1 metal.

Give two differences between the properties of tungsten and the properties of potassium.

Tungsten oxide reacts with hydrogen to give tungsten (W) and water.

The equation for the reaction is:

The law of conservation of mass states:

‘The mass of the products equals the mass of the reactants during a chemical reaction.’

Show that the equation obeys the law of conservation of mass.

Relative atomic mass (A_r): W = 184

Relative formula masses (M_r): H₂ = 2 WO₃ = 232 H₂O = 18

The reaction producing tungsten has a high atom economy.

Why is it important to use reactions with a high atom economy in industry?

The elements in Group 7 of the periodic table are known as the halogens.

Figure 4 shows information about some of the elements in Group 7.

Predict the boiling point of chlorine.

Use Figure 4.

What is the state of fluorine at –250 °C?

Use Figure 4.

Astatine (At) is an element in Group 7.

What is the number of electrons in the outer shell of an astatine atom?

Hydrogen reacts with astatine to produce hydrogen astatide.

Predict the formula of hydrogen astatide.

Explain the trend in reactivity of the elements going down Group 7.

A more reactive halogen can displace a less reactive halogen from a solution of its salt.

Write a balanced equation for the reaction between bromine and potassium iodide.

This question is about small particles.

Before the discovery of the electron, atoms were thought to be tiny spheres that could not be divided.

The discovery of the electron led to the plum pudding model of the atom.

Describe the plum pudding model of the atom.

The model of the atom changed again after the alpha particle scattering experiment.

Give two conclusions that were made from the alpha particle scattering experiment.

Niels Bohr made another change to the model of the atom.

What was this change?

A helium atom has a radius of 1.4 × 10^–10 m.

The nucleus of this atom has a radius of 1.7 × 10^–15 m.

How many times larger is the radius of the atom than the radius of the nucleus?

Tick () one box.

Nanoparticles contain a few hundred atoms.

Figure 5 represents a cubic nanoparticle.

Calculate the simplest surface area: volume ratio of the cubic nanoparticle.

Lenses in reading glasses often have a scratch-resistant coating that contains a hard substance.

Nanoparticles of the hard substance are used instead of fine particles of the hard substance.

Explain why nanoparticles are used instead of fine particles.

Aluminium is extracted by the electrolysis of a molten mixture.

The mixture contains aluminium oxide and one other substance.

Aluminium oxide is an ionic compound.

Explain why aluminium oxide has a very high melting point.

Name the substance added to aluminium oxide to form the mixture.

Give one reason why a mixture is used as the electrolyte.

Oxygen is produced at the positive electrode.

Write the half equation for the reaction that produces oxygen at the positive electrode.

The positive electrode must be continually replaced.

Explain why.

Hydrazine (N₂H₄) is a compound of nitrogen and hydrogen.

Scientists are researching the use of hydrazine in fuel cells.

Table 2 gives some information about the use of hydrogen and hydrazine in fuel cells.

Evaluate the use of hydrazine instead of hydrogen in a fuel cell.

Figure 6 shows a model of the hydrazine molecule.

Complete the dot and cross diagram for hydrazine in Figure 7.

Show the outer shell electrons only.

Give one advantage of the ball and stick model in Figure 6 compared to the dot and cross diagram.

Figure 8 shows the displayed formula equation for the reaction of hydrazine with oxygen.

The reaction is exothermic.

The energy released forming new bonds is 581 kJ/mol greater than the energy needed to break existing bonds.

Table 3 shows some bond energies.

Calculate the bond energy (X) of the bond.

This question is about alkalis and acids.

What is the formula of the ion that all alkalis contain when in solution?

A student planned a titration experiment to determine the concentration of a sodium hydroxide solution.

This is the student’s plan.

1. Measure 25.0 cm³ of sulfuric acid of known concentration using a pipette.

2. Add the sulfuric acid to a conical flask.

3. Add 3 drops of universal indicator to the conical flask.

4. Place the conical flask on a white tile.

5. Fill a burette with sodium hydroxide solution to the 0.00 cm³ mark.

6. Add sodium hydroxide solution to the conical flask and swirl the flask.

7. Stop adding sodium hydroxide solution when there is a colour change.

8. Record the volume of sodium hydroxide solution used.

9. Repeat steps 1 to 8 until consistent results are obtained.

Suggest two improvements to the plan.

Give one reason for each improvement.

Figure 9 shows the burette after one titration.

What is the reading on the burette?

In a different titration, 25.0 cm³ of 0.216 mol/dm³ sulfuric acid needed 11.25 cm³ of sodium hydroxide solution for neutralisation.

The equation for the reaction is:

Calculate the concentration of the sodium hydroxide solution.

Table 4 gives information about solutions of two acids.

Which is a correct statement about the solutions of HC l and HCN in Table 4 ?

Tick () one box.

In Table 4, the solution of HC l has a lower pH than the solution of HCN.

Explain why.

Use the data in Table 4.

Zinc reacts with iodine to produce the salt zinc iodide.

The reaction is done in a solution using ethanol as the solvent.

Ethanol is a flammable liquid with a boiling point of 78 °C.

Table 5 shows the solubility of zinc, iodine and zinc iodide in ethanol.

Plan a method to obtain crystals of zinc iodide from zinc and iodine.

A student used 6.35 g of iodine in the reaction.

6.29 g of zinc iodide was produced.

The equation for the reaction is:

Calculate the percentage yield of zinc iodide.

Give your answer to 3 significant figures.

Relative formula masses (M_r): I₂ = 254 ZnI₂ = 319