AQA GCSE Trilogy Chemistry Paper 2 Foundation June 2023 question paper 8464/C/2F

Crude oil contains a large number of hydrocarbons.

Crude oil is a finite resource. What is a finite resource? Tick (✓) one box.

What is crude oil formed from? Tick (✓) one box.

What type of substance is crude oil? Tick (✓) one box.

The hydrocarbons in crude oil are separated into fractions using fractional distillation. Complete the sentences. Choose answers from the box.

In fractional distillation the crude oil is heated so

Hydrocarbons can be cracked to produce more useful molecules.

Complete the sentence. Choose the answer from the box.

Hydrogen gas is a product of cracking. What is used in the test for hydrogen gas? Tick (✓) one box.

5.20 kg of crude oil contains 1.53 kg of LPG (Liquefied Petroleum Gas). Calculate the percentage (%) of LPG in 5.20 kg of crude oil. Give your answer to 3 significant figures.

The Earth’s atmosphere is always changing.

Gases in the Earth’s early atmosphere caused changes on the Earth. Draw one line from each change to the gas that caused the change.

Gas that caused the Change change

Table 1 shows the percentage of some gases in the atmospheres of Earth and Mars today.

Which gas has the highest percentage in the Earth’s atmosphere?

Calculate how many times more carbon dioxide there is in the atmosphere of Mars than in the atmosphere of Earth. Use Table 1. Give your answer in standard form.

Carbon dioxide is a greenhouse gas.

Figure 1 shows the concentration of carbon dioxide in the Earth’s atmosphere from 1960 to 2020.

How has the concentration of carbon dioxide in the Earth’s atmosphere changed from 1960 to 2020? Tick (✓) one box.

Cars emit carbon dioxide. A car emits 17.2 kg of carbon dioxide on a journey. There are four people in the car. Calculate the mass of carbon dioxide emitted per person.

Planting trees helps to reduce climate change, because trees use carbon dioxide from the Earth’s atmosphere. Name the process in trees which uses carbon dioxide.

Figure 2 shows the annual change in forest area in four different parts of the world.

Give two conclusions about the annual change in forest area.

Methane is a greenhouse gas. Figure 3 shows sources of methane emissions.

Determine the percentage (%) of methane emissions from landfill.

Figure 4 shows two ways (A and B) of preventing used items going to landfill.

Name A and B. Choose answers from the box.

Some types of water contain dissolved substances.

A student investigated the mass of dissolved solids in distilled water and in sea water. Figure 5 shows the apparatus.

This is the method used.

1. Weigh an evaporating basin.

2. Add a sample of distilled water to the evaporating basin.

3. Weigh the evaporating basin and the water sample.

4. Heat the water sample.

5. Weigh the evaporating basin and contents.

6. Repeat steps 1 to 5 two more times.

7. Repeat steps 1 to 6 with sea water.

Give one safety precaution the student should take.

The method used did not give valid results. Which two improvements could the student make to give valid results? Tick (✓) two boxes.

A different student used a method which gave valid results. Table 2 shows the results.

The student concludes that distilled water is pure. Suggest one reason why.

Tap water is potable. One step in producing potable water is sterilisation.

Why is potable water sterilised?

Tick (✓) one box.

Chlorine is used to sterilise water. The reaction between chlorine and water is reversible. Complete the sentence.

Equilibrium is reached when the forward and reverse reactions

The test for chlorine uses damp litmus paper. Complete the sentence. Choose the answer from the box.

When damp litmus paper is put into chlorine gas

There is evidence that adding fluoride ions to drinking water reduces tooth decay.

Figure 6 shows the percentage of people showing tooth decay.

Compare the effects of adding fluoride ions to drinking water on tooth decay in people between the ages of 25 and 74. Use data from Figure 6.

Student A says that water companies should add fluoride ions to all drinking water. Student B disagrees. Suggest one reason why Student B may think that fluoride ions should not be added to all drinking water.

A catalyst is used to increase the rate of decomposition of hydrogen peroxide.

Hydrogen peroxide decomposes to produce water and oxygen. Write a word equation for the reaction.

A student investigated the rate of decomposition of hydrogen peroxide using three different catalysts:

• manganese dioxide

• copper oxide

• zinc oxide.

Figure 7 shows the apparatus.

This is the method used.

1. Measure 25 cm³ of hydrogen peroxide solution into a flask.

2. Add 0.5 g of manganese dioxide catalyst to the flask.

3. Attach a gas syringe to the flask.

4. Measure the volume of oxygen produced every 20 seconds for 120 seconds.

5. Repeat steps 1 to 4 two more times.

6. Repeat steps 1 to 5 using copper oxide catalyst.

7. Repeat steps 1 to 5 using zinc oxide catalyst.

Which two control variables are used in the investigation? Tick (✓) two boxes.

Table 3 shows the results with manganese dioxide catalyst.

Figure 8 shows a graph of the results with copper oxide catalyst and with zinc oxide catalyst.

Complete Figure 8. You should:

• plot the data for the manganese dioxide catalyst from Table 3

• draw a line of best fit.

The first two points have been plotted for you.

Which is the best catalyst? Give one reason for your answer. Use the completed Figure 8. Tick (✓) one box.

The student repeated the investigation with manganese dioxide catalyst. The results were all close to the true value. Complete the sentence. Choose the answer from the box.

Results that are close to the true value are

The student repeated the investigation using manganese dioxide catalyst at a higher temperature. Complete the sentence. Choose the answer from the box.

The combustion of fuels is a source of atmospheric pollutants.

Methane is a fuel. Balance the equation for the combustion of methane.

Many fuels are mixtures. Petrol and diesel are mixtures of hydrocarbons. Table 4 shows properties of petrol and of diesel.

Compare the properties of petrol and diesel. Use Table 4.

The gases released when a fuel is burned in car engines may include:

• oxides of nitrogen

• carbon monoxide

• water vapour.

Which chemical element do all these gases contain? Tick (✓) one box.

When diesel burns in car engines, oxides of nitrogen are produced. Where does the nitrogen come from?

When diesel burns, particulates may be produced. What environmental effect do particulates from burning diesel cause?

Carbon monoxide may be produced when diesel burns. Give one reason why carbon monoxide is difficult to detect.

Explain why water vapour and not liquid water is produced when diesel burns.

Sulfur is a common impurity in diesel. Explain why this causes an environmental problem.

Chromatography is used to separate mixtures.

Chromatography involves a mobile phase and one other phase.

What is the other phase in chromatography? Tick (✓) one box.

Why do the substances in the mixture separate in the mobile phase?

How many spots will be produced on the chromatogram of a pure compound?

In a chromatography experiment, a blue colour moved 4.77 cm. The solvent moved 5.30 cm. Calculate the R_f value for the blue colour.

Black ink is a mixture of several colours. Plan an experiment using paper chromatography to:

• separate the colours in black ink

• identify the colours from their R_f values.