AQA GCSE Chemistry Paper 2 Foundation June 2022 question paper 8462/2F

This question is about water.

A student investigated pure water. The student measured:

• the boiling point of pure water

• the pH of pure water.

Complete the sentences. Choose answers from the box.

What could the student use to measure the pH of pure water?

A different student investigated sea water. Sea water contains dissolved solids.

This is the method used.

1. Measure a 50 cm³ sample of the sea water.

2. Heat the sample until all the water has evaporated.

3. Measure the mass of solid that remains.

4. Repeat steps 1 to 3 three more times.

Which two pieces of equipment were needed in this investigation? Tick (✓) two boxes.

Table 1 shows the results.

Calculate the mean mass of solid that remained.

A 50 cm³ sample of sea water from a different source contained 1.50 g of dissolved solids. Calculate the mass of dissolved solids in 1000 cm³ of this sea water.

Sodium chloride is a dissolved solid in sea water. Sodium chloride contains sodium ions and chloride ions.

Complete the sentence. Choose the answer from the box.

The student tested sea water for sodium ions using a flame test.

Complete the sentence. Choose the answer from the box.

The student tested sea water for chloride ions by adding nitric acid and silver nitrate solution.

This question is about hydrocarbons in crude oil.

Table 2 shows information about three fractions obtained from crude oil.

Figure 1 shows the fractionating column used to separate fractions A, B and C.

The temperature of the fractionating column is:

• 30 °C at the top

• 400 °C at the bottom.

Complete Figure 1 to show where fractions A, B and C are collected.

Table 3 shows information about three fractions obtained from crude oil.

Complete the sentences. Choose answers from the box.

Table 4 shows the percentage of two fractions obtained from two different sources of crude oil.

Complete Figure 2. You should:

• complete the y-axis scale

• plot the percentage of the heavy fuel oil fraction obtained from source K.

Use Table 4.

Kerosene is in higher demand than heavy fuel oil. Suggest why crude oil from source J is in higher demand than crude oil from source K. Use Table 4.

Large hydrocarbon molecules can be cracked to produce smaller hydrocarbon molecules including alkanes.

Which two of the following can be used to crack large hydrocarbon molecules? Tick (✓) two boxes.

Alkanes have the general formula C_nH_2n+2 Complete the formula of the alkane molecule containing 11 carbon atoms.

C₂H₆ is an alkane. Which type of bond is found in a C₂H₆ molecule? Tick (✓) one box.

Which two substances are produced when alkanes completely combust? Tick (✓) two boxes.

This question is about the Earth’s atmosphere. Table 5 shows:

• the estimated percentages of gases in the Earth’s early atmosphere

• the percentages of gases in the Earth’s atmosphere today.

Calculate value X in Table 5.

Which two other gases may have been in the Earth’s early atmosphere? Tick () two boxes.

Algae and plants increased the percentage of oxygen in the Earth’s atmosphere. The same process in algae and plants decreased the percentage of carbon dioxide in the Earth’s atmosphere.

Which process in algae and plants increased the percentage of oxygen in the Earth’s atmosphere? Tick (✓) one box.

Which two other processes decreased the percentage of carbon dioxide in the Earth’s atmosphere? Tick (✓) two boxes.

Figure 3 shows how the percentages of gases in the Earth’s atmosphere may have changed since the atmosphere was formed.

When was the percentage of oxygen in the Earth’s atmosphere 8%? Use Figure 3.

When did the percentage of nitrogen in the Earth’s atmosphere become constant? Use Figure 3.

Crude oil was formed from an ancient biomass as the Earth’s atmosphere evolved. What did this ancient biomass mainly consist of? Tick (✓) one box.

Most of the percentages of the gases in Figure 3 are estimated values. Why have scientists used estimated values for the percentages of the gases in Figure 3 ?

This question is about ethanol.

The formula of ethanol is C₂H₅OH Complete the displayed structural formula of ethanol.

Which is one use of ethanol? Tick (✓) one box.

Ethanol is used as a solvent in some inks. A student used paper chromatography to show that an ink contained two different dyes. Figure 4 shows the apparatus at the end of the investigation.

Describe a method the student could have used for the investigation.

Ethanol can be produced from sugar solution by fermentation. What must be added to sugar solution to produce ethanol?

E5 and E10 are types of fuel used in cars. These fuels contain ethanol and petrol. Table 6 shows information about E5 and E10.

Calculate the mass of ethanol in 4.4 kg of E5. Give your answer in grams. Use Table 6.

The ethanol in E5 and E10 is produced from sugar. Sugar is produced from plants. Explain why the production of E10 removes more carbon dioxide from the atmosphere than the production of E5. Use Table 6.

Table 7 shows the energy content of ethanol and petrol.

Suggest one disadvantage of using E10 instead of E5. Complete the sentence. A disadvantage of using E10 is that

Ammonia is produced in the Haber process. The raw materials for the Haber process are nitrogen and hydrogen.

Draw one line from each raw material to the source of that raw material.

What are the states of nitrogen and of hydrogen when used in the Haber process? Tick (✓) one box. State of nitrogen State of hydrogen

The word equation for the production of ammonia is: nitrogen + hydrogen ⇌ ammonia The atom economy of the reaction is 100%.

How does the word equation show that the atom economy is 100%? Tick (✓) one box.

Figure 5 represents the Haber process.

A mixture of nitrogen, hydrogen and ammonia enters X.

Complete the sentences. Choose answers from the box.

In X, the mixture is cooled. The ammonia can be removed from X because the ammonia is

The unreacted nitrogen and hydrogen are

Table 8 shows the percentage yield of ammonia at different pressures.

Plot the data from Table 8 on Figure 6. Draw a line of best fit.

What is the effect of increasing the pressure on the percentage yield of ammonia? Use Table 8.

A student investigated the rate of reaction between sodium thiosulfate solution and hydrochloric acid. Figure 7 shows the apparatus used.

When hydrochloric acid is added to sodium thiosulfate solution, the mixture gradually becomes cloudy. A smaller percentage of light from the light source reaches the light sensor as the mixture becomes more cloudy.

This is the method used.

1. Measure 50 cm³ of sodium thiosulfate solution into the beaker.

2. Add 10 cm³ of hydrochloric acid to the sodium thiosulfate solution.

3. Immediately start a timer.

4. Record the percentage of light from the light source that reaches the light sensor every 20 seconds for 120 seconds.

Balance the equation for this reaction.

The mixture becomes cloudy because the sulfur produced is a solid. What is the state symbol for a solid? Tick (✓) one box.

The student monitored the cloudiness of the reaction mixture using a light sensor. What other piece of equipment could be used to monitor the cloudiness of the reaction mixture? Tick (✓) one box.

Figure 8 shows the results.

What happened to the rate of reaction between 40 and 60 seconds? Use Figure 8. Tick (✓) one box.

The student stopped taking measurements after 120 seconds because the percentage of light reaching the sensor stayed constant. Why did the percentage of light reaching the sensor stay constant? Tick (✓) one box.

The student repeated the experiment using sodium thiosulfate solution of a higher concentration. How would the line of best fit for sodium thiosulfate solution of a higher concentration compare with the line of best fit on Figure 8 ? Tick (✓) one box.

The student then investigated the effect of changing the temperature on the rate of reaction. The student used sodium thiosulfate solution and hydrochloric acid which had been kept in an ice bath. Which are two effects of using reactants kept in an ice bath rather than at room temperature? Tick (✓) two boxes.

This question is about fertilisers. Ammonium nitrate is a fertiliser containing nitrogen.

Complete the sentence. Choose the answer from the box.

Ammonium nitrate is produced by reacting ammonia with

Ammonium nitrate fertiliser is sold in 600 kg bags. A farmer spreads 40 bags of ammonium nitrate fertiliser on land with an area

Calculate the mass of ammonium nitrate fertiliser spread per m² of land.

A scientist works for a company which makes ammonium nitrate fertiliser. The scientist investigates the effect of different fertilisers on crop growth. The scientist concludes that the ammonium nitrate fertiliser improves crop growth more than other fertilisers. Suggest one reason why this conclusion might not be valid.

A different fertiliser containing nitrogen has the formula K₂NH₄PO₄

How many atoms of nitrogen are in the formula K₂NH₄PO₄?

Nitrogen and potassium in the fertiliser K₂NH₄PO₄ are important for good crop growth. Which other element in the fertiliser K₂NH₄PO₄ is important for good crop growth? Tick (✓) one box.

Some fertilisers are mixtures of different compounds in fixed proportions. What name is given to a mixture of different compounds in fixed proportions?

This question is about copper wire and copper compounds.

Copper is used to make electrical wires. Figure 9 shows how copper electrical wire is insulated using an addition polymer called poly(butene).

The addition polymer poly(butene) has the displayed structural formula:

Poly(butene) is produced from the monomer butene. Complete Figure 10 to show the displayed structural formula of butene.

Copper can be obtained by recycling scrap copper wire.

Suggest why poly(butene) insulation must be removed from scrap copper wire before the copper is recycled.

Describe how scrap copper wire can be recycled to make new copper water pipes.

Suggest two reasons why recycling scrap copper is more sustainable than extracting copper from copper ores.

Copper sulfate is a compound of copper. Copper sulfate solution contains copper(II) ions and sulfate ions.

A solution can be added to copper sulfate solution to show the presence of copper(II) ions. Name the solution added. Give the result of the test. Name of solution added

Describe one test to show the presence of sulfate ions in copper sulfate solution. Give the result of the test.

A student investigated the change in mass when hydrated cobalt chloride was heated. The word equation for the reaction is: hydrated cobalt chloride ⇌ anhydrous cobalt chloride + water

This is the method used.

1. Add 2.0 g of hydrated cobalt chloride to an empty test tube.

2. Measure the mass of the test tube and contents.

3. Heat the test tube and contents gently for 30 seconds.

4. Allow the test tube and contents to cool.

5. Measure the mass of the test tube and contents.

6. Repeat steps 3 to 5 until the mass of the test tube and contents does not change.

Table 9 shows the results.

Determine the mass of the empty test tube.

Explain why the mass of the test tube and contents decreased.

Suggest why the test tube and contents were heated until the mass did not change.

Energy is taken in from the surroundings when hydrated cobalt chloride is heated.

When 238 g of hydrated cobalt chloride is heated until the mass does not change, 88.1 kJ of energy is taken in. The student heated 2.00 g of hydrated cobalt chloride until the mass did not change.

Calculate the energy taken in during this reaction. Give your answer to 3 significant figures.

What type of reaction takes place when hydrated cobalt chloride is heated?

This question is about life cycle assessments (LCAs).

Milk bottles can be made from glass or from a polymer. Table 10 shows information about milk bottles of equal volume.

Evaluate the use of glass for milk bottles compared with the use of a polymer for milk bottles. Use features of life cycle assessments (LCAs) in your answer. Use Table 10.

Milk is also sold in cardboard cartons. A carton is made using 40 cm³ of cardboard.

Calculate the mass of the carton. Use the equation: