AQA GCSE Chemistry Paper 1 Higher June 2019 question paper 8462/1H

This question is about the periodic table. In the 19th century, some scientists tried to classify the elements by arranging them in order of their atomic weights. Figure 1 shows the periodic table Mendeleev produced in 1869. His periodic table was more widely accepted than previous versions.

The atomic weight of tellurium (Te) is 128 and that of iodine (I) is 127 Why did Mendeleev reverse the order of these two elements?

Mendeleev left spaces marked with an asterisk * He left these spaces because he thought missing elements belonged there. Why did Mendeleev’s periodic table become more widely accepted than previous versions?

Mendeleev arranged the elements in order of their atomic weight. What is the modern name for atomic weight?

Tick (✓) one box.

Complete the sentence. In the modern periodic table, the elements are arranged in order of

Chlorine, iodine and astatine are in Group 7 of the modern periodic table.

Astatine (At) is below iodine in Group 7. Predict:

• the formula of an astatine molecule

• the state of astatine at room temperature.

Formula of astatine molecule State at room temperature

Sodium is in Group 1 of the modern periodic table. Describe what you would see when sodium reacts with chlorine.

This question is about acids and alkalis.

Which ion do all acids produce in aqueous solution? Tick (✓) one box.

Calcium hydroxide solution reacts with an acid to form calcium chloride. Complete the word equation for the reaction.

A student investigates the volume of sodium hydroxide solution that reacts with 25.0 cm³ of dilute sulfuric acid. Figure 2 shows the apparatus the student uses.

Use Figure 2 to answer Questions 02.3 and 02.4

Name apparatus A.

What is the reading on apparatus A ?

The higher the concentration of a sample of dilute sulfuric acid, the greater the volume of sodium hydroxide needed to neutralise the acid. The student tested two samples of dilute sulfuric acid, P and Q. Describe how the student could use titrations to find which sample, P or Q, is more concentrated.

This question is about materials and their properties.

Figure 3 shows a carbon nanotube.

The structure and bonding in a carbon nanotube are similar to graphene. Carbon nanotubes are used in electronics because they conduct electricity. Explain why carbon nanotubes conduct electricity.

Figure 4 shows a badminton racket.

Table 1 shows some properties of materials. The materials could be used to make badminton racket frames.

Evaluate the use of the materials to make badminton racket frames. Use Table 1.

Zinc oxide can be produced as nanoparticles and as fine particles.

A nanoparticle of zinc oxide is a cube of side 82 nm Figure 5 represents a nanoparticle of zinc oxide.

Calculate the surface area of a nanoparticle of zinc oxide. Give your answer in standard form.

Some suncreams contain zinc oxide as nanoparticles or as fine particles. Suggest one reason why it costs less to use nanoparticles rather than fine particles in suncreams.

This question is about atomic structure.

Atoms contain subatomic particles. Table 2 shows properties of two subatomic particles. Complete Table 2.

An element X has two isotopes. The isotopes have different mass numbers.

Define mass number.

Why is the mass number different in the two isotopes?

The model of the atom changed as new evidence was discovered. The plum pudding model suggested that the atom was a ball of positive charge with electrons embedded in it. Evidence from the alpha particle scattering experiment led to a change in the model of the atom from the plum pudding model. Explain how.

This question is about ammonia, NH₃

Complete the dot and cross diagram for the ammonia molecule shown in Figure 6. Show only the electrons in the outer shell of each atom.

Give one limitation of using a dot and cross diagram to represent an ammonia molecule.

Explain why ammonia has a low boiling point. You should refer to structure and bonding in your answer.

Ammonia reacts with oxygen in the presence of a metal oxide catalyst to produce nitrogen and water.

Which metal oxide is most likely to be a catalyst for this reaction? Tick (✓) one box.

Figure 7 shows the displayed formula equation for the reaction.

Table 3 shows some bond energies.

Calculate the overall energy change for the reaction. Use Figure 7 and Table 3.

Explain why the reaction between ammonia and oxygen is exothermic. Use values from your calculation in Question 05.5

Figure 8 shows the reaction profile for the reaction between ammonia and oxygen. Complete Figure 8 by labelling the:

• activation energy

• overall energy change.

This question is about chemical cells. A student investigated the voltage produced by different chemical cells. Figure 9 shows the apparatus.

This is the method used.

1. Use cobalt as electrode X.

2. Record the cell voltage.

3. Repeat steps 1 and 2 using different metals as electrode X.

Suggest two control variables used in this investigation.

Table 4 shows the student’s results.

Write the six metals used for electrode X in order of reactivity. Use Table 4. Justify your order of reactivity.

Which of the following pairs of metals would produce the greatest voltage when used as the electrodes in the cell? Use Table 4. Tick (✓) one box.

Hydrogen fuel cells can be used to power different forms of transport. Some diesel trains are being converted to run on hydrogen fuel cells. A newspaper article referred to the converted trains as the new ‘steam trains’. Suggest why.

This question is about electrolysis. Aluminium is produced by electrolysing a molten mixture of aluminium oxide and cryolite.

Explain why a mixture is used as the electrolyte instead of using only aluminium oxide.

What happens at the negative electrode during the production of aluminium? Tick (✓) one box.

Oxygen is produced at the positive electrode. Complete the balanced half-equation for the process at the positive electrode.

Explain why the positive electrode must be continually replaced.

The overall equation for the electrolysis of aluminium oxide is:

Calculate the mass of oxygen produced when 2000 kg of aluminium oxide is completely electrolysed. Relative atomic masses (A_r): O = 16 Al = 27

Sodium metal and chlorine gas are produced by the electrolysis of molten sodium chloride.

Explain why sodium chloride solution cannot be used as the electrolyte to produce sodium metal.

Calculate the volume of 150 kg of chlorine gas at room temperature and pressure. The volume of one mole of any gas at room temperature and pressure is 24.0 dm³ Relative formula mass (M_r): Cl₂ = 71

Copper forms two oxides, Cu₂O and CuO A teacher investigated an oxide of copper. Figure 10 shows the apparatus.

This is the method used.

1. Weigh empty tube A.

2. Add some of the oxide of copper to tube A.

3. Weigh tube A and the oxide of copper.

4. Weigh tube B and drying agent.

5. Pass hydrogen through the apparatus and light the flame at the end.

6. Heat tube A for 2 minutes.

7. Reweigh tube A and contents.

8. Repeat steps 5 to 7 until the mass no longer changes.

9. Reweigh tube B and contents.

10. Repeat steps 1 to 9 with different masses of the oxide of copper.

Suggest one reason why step 8 is needed.

Explain why the excess hydrogen must be burned off.

Figure 10 is repeated here.

Table 5 shows the teacher’s results.

When an oxide of copper is heated in a stream of hydrogen, the word equation for the reaction is: copper oxide + hydrogen → copper + water

Determine the mass of copper and the mass of water produced in this experiment. Use Table 5.

The teacher repeated the experiment with a different sample of the oxide of copper. The teacher found that the oxide of copper produced 2.54 g of copper and 0.72 g of water. Two possible equations for the reaction are:

Determine which is the correct equation for the reaction in the teacher’s experiment. Relative atomic masses (A_r): H = 1 O = 16 Cu = 63.5

A student investigated the temperature change in the reaction between dilute sulfuric acid and potassium hydroxide solution. This is the method used.

1. Measure 25.0 cm³ potassium hydroxide solution into a polystyrene cup.

2. Record the temperature of the solution.

3. Add 2.0 cm³ dilute sulfuric acid.

4. Stir the solution.

5. Record the temperature of the solution.

6. Repeat steps 3 to 5 until a total of 20.0 cm³ dilute sulfuric acid has been added.

Suggest why the student used a polystyrene cup rather than a glass beaker for the reaction.

Table 6 shows some of the student’s results.

Figure 11 shows some of the data from the investigation.

Complete Figure 11:

• plot the data from Table 6

• draw a line of best fit through these points

• extend the lines of best fit until they cross.

Determine the volume of dilute sulfuric acid needed to react completely with 25.0 cm³ of the potassium hydroxide solution. Use Figure 11.

Determine the overall temperature change when the reaction is complete. Use Figure 11.

The student repeated the investigation. The student used solutions that had different concentrations from the first investigation. The student found that 15.5 cm³ of 0.500 mol/dm³ dilute sulfuric acid completely reacted with 25.0 cm³ of potassium hydroxide solution. The equation for the reaction is:

Calculate the concentration of the potassium hydroxide solution in mol/dm³ and in

Relative atomic masses (A_r): H = 1 O = 16 K = 39