AQA GCSE Trilogy Chemistry Paper 1 Higher June 2019 question paper 8464/C/1H

This question is about reactions of metals. Figure 1 shows what happens when calcium, copper, magnesium and zinc are added to hydrochloric acid.

What is the order of decreasing reactivity of these four metals? Tick (✓) one box.

A student wants to make a fair comparison of the reactivity of the metals with hydrochloric acid.

Name two variables that must be kept constant.

What is the independent variable in this reaction?

Predict the reactivity of beryllium compared with magnesium. Give a reason for your answer. Use the periodic table.

A solution of hydrochloric acid contains 3.2 g of hydrogen chloride in 50 cm³ Calculate the concentration of hydrogen chloride in g per dm³

This question is about salts. Ammonium nitrate solution is produced when ammonia gas reacts with nitric acid.

Give the state symbol for ammonium nitrate solution.

What is the formula of nitric acid? Tick (✓) one box.

Ammonia gas dissolves in water to produce ammonia solution. Ammonia solution contains hydroxide ions, OH^– A student adds universal indicator to solutions of nitric acid and ammonia. What colour is observed in each solution?

Colour in nitric acid Colour in ammonia solution

The student gradually added nitric acid to ammonia solution. Which row, A, B, C or D, shows the change in pH as the nitric acid is

Calculate the percentage by mass of oxygen in ammonium nitrate (NH₄NO₃). Relative atomic masses (A_r): H = 1 N = 14 O = 16 Relative formula mass (M_r): NH₄NO₃ = 80

Describe a method to investigate how the temperature changes when different masses of ammonium nitrate are dissolved in water. You do not need to write about safety precautions.

This question is about oxygen.

Hydrogen reacts with oxygen.

Figure 2 shows the relative energies of the reactants and products at a certain temperature.

Label the activation energy on Figure 2.

Determine the overall energy change for the reaction between hydrogen and oxygen shown in Question 03.1 Use Figure 2.

Oxygen is in Group 6 of the periodic table. Figure 3 shows the outer energy levels in one molecule of oxygen (O₂). Draw the electrons in the outer energy levels in Figure 3.

The equation shows the decomposition of hydrogen peroxide. 2 H – O – O – H → 2 H – O – H + O=O Table 1 shows the bond energies.

Calculate the overall energy change for the reaction.

This question is about elements in the periodic table.

What order did scientists use to arrange elements in early periodic tables?

In the early periodic tables some elements were placed in the wrong groups. Mendeleev overcame this in his periodic table. Give one way Mendeleev did this.

Table 2 shows the boiling points of fluorine, chlorine and bromine.

Explain why the boiling points in Table 2 are low.

Explain the trend in the boiling points in Table 2.

Explain why neon is unreactive. Give the electronic structure of neon in your answer.

How many atoms are there in 1 g of argon? The Avogadro constant is 6.02 × 10²³ per mole. Relative atomic mass (A_r): Ar = 40

This question is about electrolysis.

Some metals are extracted from molten compounds using electrolysis. Why is electrolysis used to extract some metals?

Aluminium is produced by electrolysis of a molten mixture. What two substances does the molten mixture contain?

Copper and chlorine are produced when molten copper chloride is electrolysed. Complete the half equation for the reaction at each electrode.

Half equation at negative electrode

Half equation at positive electrode

Figure 4 shows the apparatus a student used to electrolyse copper chloride solution.

The student:

• measured the mass of copper deposited on the negative electrode after 60 minutes

• compared the mass deposited with the expected value.

Suggest two reasons why the mass deposited was different from the expected value.

Figure 5 shows the expected mass of copper produced each minute.

Determine the expected mass of copper after 24 hours. Use Figure 5.

Silver nitrate solution is electrolysed. Figure 6 shows the change in mass of the negative electrode over 10 hours.

Determine the mass of the negative electrode at the start of the experiment. Use Figure 6.

Calculate the gradient of the line in Figure 6. Give the unit.

This question is about sodium.

Sodium reacts with chlorine. What is the balanced equation for the reaction?

Tick (✓) one box.

Hot sodium is put in a gas jar of chlorine. Describe the observations made before, during and after the reaction.

Explain why sodium is less reactive than potassium.

Chlorine reacts with sodium and with hydrogen. Compare the structure and bonding in sodium chloride and hydrogen chloride.