AQA GCSE Trilogy Chemistry Paper 2 Higher June 2022 question paper 8464/C/2H

A student investigated the colours in a brown ink using chromatography.

Figure 1 shows the apparatus used.

Give two errors made by the student. Describe the problem each error would cause.

A different student set up the apparatus correctly. Figure 2 shows the results.

Give two conclusions the student can make from Figure 2 about the four colours in the brown ink.

Why was the green colour still on the start line at the end of the experiment? Tick (✓) one box.

A student calculated the R_f value of a colour to be 0.24 The colour moved 1.8 cm from the start line. Calculate the distance the solvent moved. Use the equation:

Water that is safe to drink is called potable water. Compare how easily potable water can be obtained from:

• waste water (sewage)

• ground water (fresh water).

A scientist produced potable water from 150 cm³ of salty water.

Which process can be used to produce potable water from salty water? Tick (✓) one box.

The salty water contains sodium chloride. The scientist collected 2.40 g of sodium chloride from 150 cm³ of salty water. Calculate the concentration of sodium chloride in grams per dm³

This question is about the reaction between sodium thiosulfate solution and hydrochloric acid. The equation for the reaction is:

The mass of the conical flask and contents was greater at the start of the reaction than at the end. Explain why.

A teacher demonstrated the reaction between sodium thiosulfate solution and hydrochloric acid. Figure 3 shows the experiment. The experiment was done in a fume cupboard.

This is the method the teacher used.

1. Pour 50 cm³ of sodium thiosulfate solution into a conical flask.

2. Put the conical flask on a black cross drawn on a piece of paper.

3. Pour 10 cm³ of hydrochloric acid into the conical flask and start a timer.

4. Stop the timer when the cross can no longer be seen.

5. Repeat the experiment at different temperatures.

What type of variable is time in this reaction? Tick (✓) one box.

Table 1 shows the results.

Complete Figure 4. You should:

• plot the data from Table 1 on Figure 4

• draw a line of best fit.

A student investigated the effect of concentration of sodium thiosulfate on the time taken for the reaction at room temperature. Figure 5 shows the results with a tangent drawn at 0.4 mol/dm³

Calculate the gradient (slope) of the tangent at 0.4 mol/dm³ Give the unit.

The student determined the rate of the reaction at regular time intervals during an experiment. Explain why the rate decreased during the reaction. You should give your answer in terms of particles.

This question is about hydrocarbons and the uses of hydrocarbons.

Figure 6 shows a model of an alkane.

What is the name of the alkane in Figure 6 ?

What is a hydrocarbon?

Large hydrocarbon molecules are cracked.

When C₁₁H₂₄ is cracked, three products are formed. Complete the equation for the reaction.

Explain why one of the products of cracking is in high demand.

Window frames can be manufactured from wood or from plastic. Table 2 shows data from a life cycle assessment (LCA) for a wooden window frame and a plastic window frame. Both window frames are the same size.

Evaluate the sustainability of wooden and plastic window frames.

You should include environmental and economic factors.

This question is about the Earth’s atmosphere and the Earth’s resources.

After the formation of the Earth’s early atmosphere, the amounts of nitrogen and oxygen in the atmosphere changed. Explain the main changes in the amounts of nitrogen and oxygen in the Earth’s atmosphere.

Describe how coal was formed from the carbon dioxide present in the Earth’s early atmosphere.

The combustion of 1.0 kg of coal produces more carbon dioxide than the combustion of 1.0 kg of natural gas. Suggest why.

Metals are extracted from metal ores found in the Earth.

Describe how bioleaching is used to extract copper from low grade ores.

Phytomining uses plants to extract nickel from low grade ores. The plants contain 0.792% nickel by mass. The plants are burned to produce ash. The ash from these plants contains 4.80% nickel by mass. Calculate the mass of ash produced from burning 1000 kg of plants. Give your answer in grams in standard form.

This question is about catalysts and equilibrium.

What type of substance is a catalyst in biological systems? Tick (✓) one box.

Explain how a catalyst increases the rate of a reaction.

The reversible reaction for the production of ammonia is:

What can scientists predict using Le Chatelier’s Principle?

Describe how a reversible chemical reaction is able to reach equilibrium.

Explain the effect of increasing the pressure on the yield of ammonia.

The forward reaction to produce ammonia is exothermic. Explain the effect of increasing the temperature on the yield of ammonia.