AQA GCSE Trilogy Chemistry Paper 2 Foundation November 2021 question paper 8464/C/2F

Fresh water contains low levels of dissolved salts.

Water reacts with anhydrous copper sulfate in a reversible reaction.

The word equation for the reaction is: water + anhydrous copper sulfate hydrated copper sulfate

How does the equation show that the reaction is reversible?

Complete the sentences. Choose answers from the box.

Figure 1 shows anhydrous copper sulfate in a sealed container.

Suggest one reason why anhydrous copper sulfate is kept in a sealed container.

Sodium chloride dissolves in water to form sodium chloride solution.

Draw one line from each substance to the description of the substance. Substance Description of substance

Name the process used to obtain solid sodium chloride from sodium chloride solution.

Two processes used to obtain potable water from fresh water are:

• filtering

• sterilising.

Give one reason why each process is used.

Which type of water is the easiest to obtain potable water from? Tick (✓) one box.

Which of the following is the first stage of waste water treatment? Tick (✓) one box.

Cars cause atmospheric pollution.

Figure 2 shows the percentage of cars in the UK using different energy sources.

The percentage of cars using petrol is 54%. Draw the bar for petrol on Figure 2.

Some car emissions contain nitrogen dioxide.

Table 1 shows the concentration of nitrogen dioxide in the air in three different areas for 1 week.

Which column of data has the greatest range? Tick (✓) one box.

Explain why the concentration of nitrogen dioxide in the air is lower on Sunday.

Calculate the mean value for the concentration of nitrogen dioxide in the air in the city centre for the days from Monday to Friday. Use Table 1.

Nitrogen dioxide is removed from car emissions by catalytic converters.

Which two of the following are correct statements about catalysts? Tick (✓) two boxes.

The catalyst in catalytic converters contains platinum. Platinum is an unreactive metal obtained from the Earth’s crust. Complete the sentence. Choose the answer from the box.

Platinum is a.

Emissions from cars that burn fossil fuels contain carbon dioxide. What is used to test for carbon dioxide? Tick (✓) one box.

An increase in greenhouse gases in the Earth’s atmosphere causes an increase in global temperature.

An increase in global temperature is a major cause of climate change. Give two effects of global climate change.

Carbon dioxide is a greenhouse gas. Figure 3 shows the percentage of carbon dioxide in the Earth’s atmosphere from 1750.

Describe the trend in the percentage of carbon dioxide in the Earth’s atmosphere from 1750 to 2000. Use Figure 3.

Determine the change in the percentage of carbon dioxide in the Earth’s atmosphere from 1950 to 2000. Use Figure 3.

Percentage of carbon dioxide in 1950 Percentage of carbon dioxide in 2000

Give one reason why the percentage of carbon dioxide in the atmosphere is changing.

Predict the percentage of carbon dioxide in the Earth’s atmosphere in 2050. You should extend the graph line on Figure 3.

This question is about the atmospheres of Earth and Mars.

Earth’s early atmosphere may have been like the atmosphere of Mars today. Why are scientists not certain about the percentage of gases in the Earth’s early atmosphere?

What was formed from the water vapour in the Earth’s early atmosphere? Tick (✓) one box.

The Earth’s atmosphere today consists mainly of nitrogen and oxygen. Draw one line from each gas to what produced the gas.

Table 2 shows the percentage of some gases in the atmospheres of

Earth and Mars.

Why are animals not able to live on Mars? Tick (✓) one box.

There is more carbon dioxide on Mars than on Earth. Which other gas is found in larger quantities on Mars than on Earth?

Calculate how many times more nitrogen than oxygen there is in the atmosphere of Earth. Use Table 2. Give your answer to 2 significant figures.

Industries use the Earth’s resources to produce useful products.

Figure 4 shows the world population and the world production of copper between 1900 and 2020.

How does the change in the world population compare with the world production of copper?

Tick (✓) one box.

Copper is produced from copper ore and from recycling waste copper.

The energy needed to produce 1 kg of copper from copper ore is 70 MJ. The energy needed to produce 1 kg of recycled copper is 27 MJ. Calculate the energy saved if 100 kg of copper is produced from recycled copper and not from copper ore.

Producing copper from recycling waste copper reduces emissions of sulfur dioxide. Why is reducing emissions of sulfur dioxide important?

Copper is used to make coins. A coin of mass 8 g contains 75% copper. Calculate the mass of copper in the coin.

Iron and glass are both produced from the Earth’s resources. Some processes can reduce the use of limited resources. Draw one line from the description of the process to the name of the process. Description of process Name of process

Life cycle assessments are used to assess the environmental impact of producing iron nails and glass bottles. There are four stages, A, B, C and D, in a life cycle assessment. The stages are not in the correct order.

Stage A Disposal Stage B Extracting and processing raw materials Stage C Manufacturing and packaging Stage D Use and operation

What is the correct order of stages A, B, C, and D ? Tick (✓) one box.

A student investigated the reaction between magnesium and excess hydrochloric acid. Figure 5 shows the apparatus.

This is the method used.

1. Pour 50 cm³ of hydrochloric acid into a conical flask.

2. Add a piece of magnesium.

3. Insert stopper and delivery tube and start a timer.

4. Collect the gas produced in a gas syringe.

5. Record the volume of gas produced every 20 seconds for 2 minutes.

6. Repeat steps 1 to 5 with higher concentrations of hydrochloric acid.

Give the independent variable and one control variable in this investigation. Independent variable

Table 3 shows the results from the first experiment using hydrochloric acid with a

low concentration.

Complete Figure 6. You should:

• plot the data from Table 3 (the point 0,0 has been plotted for you)

• draw a line of best fit.

How does the rate of this reaction change with time? Use Table 3. Tick (✓) one box.

The student repeated the experiment using hydrochloric acid with a higher concentration. Which statement is correct? Tick (✓) one box.

Temperature also affects the rate of the reaction. Explain how increasing the temperature affects the rate of the reaction. You should refer to particles and collisions.

Crude oil is a resource found in rocks. Most of the compounds in crude oil are hydrocarbons.

Complete the sentence.

Crude oil is formed by the decomposition of

Alkanes are hydrocarbons. Give the name of the alkane molecule that has three carbon atoms.

Figure 7 shows two alkane molecules.

Table 4 shows the melting points and boiling points of methane and hexane.

Compare the structure and properties of methane and hexane.

Hydrocarbons are cracked to produce more useful alkanes and alkenes.

Decane (C₁₀H₂₂) is cracked to produce two products. Complete the equation for the reaction.

C₂H₄ is an alkene. What is the test for alkenes? Give the result of the test if an alkene is present.