AQA GCSE Chemistry Paper 2 Foundation November 2021 question paper 8462/2F

This question is about the Earth’s atmosphere.

How long ago was the Earth formed?

Tick (✓) one box.

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

Calculate the percentage X of other gases in the Earth’s atmosphere.

Use Table 1.

The atmosphere of the early Earth is thought to have been similar to the atmosphere of Mars today.

The percentages of nitrogen and of oxygen in the Earth’s atmosphere today have changed from the percentages in the Earth’s early atmosphere.

Draw one line from each gas to the change in the percentage of that gas.

Use Table 1.

The percentage of carbon dioxide in the Earth’s early atmosphere decreased.

Which two processes caused this decrease?

Tick (✓) two boxes.

Photosynthesis also decreased the percentage of carbon dioxide in the Earth’s early atmosphere.

Photosynthesis increased the percentage of another gas.

Complete the word equation for photosynthesis.

Complete the sentence.

Scientists are not certain about the percentages of gases in the Earth’s early

atmosphere because there is a lack of.

This question is about water.

A student investigated the concentration of salt in sea water.

This is the method used.

1. Filter the sea water to remove sand.

2. Measure the mass of an empty evaporating dish.

3. Measure 50 cm³ of sea water into the evaporating dish.

4. Heat the evaporating dish and sea water.

5. Evaporate the sea water to dryness.

6. Measure the mass of the evaporating dish and salt.

What equipment should the student use to measure:

• the mass of the evaporating dish

• the volume of sea water?

Mass of evaporating dish

Volume of sea water

Table 2 shows the student’s results.

The student used 50 cm³ of sea water.

Calculate the mass of salt in 1000 cm³ of this sea water.

The salt must be completely dry.

Which two extra steps are needed to show that the salt is completely dry?

Tick (✓) two boxes.

Two students, Y and Z, distil sea water to collect water.

Figure 1 shows the apparatus used by each student to collect the water.

Students Y and Z boil the same volume of sea water for the same period of time.

Explain why student Y collects a smaller volume of water than student Z.

Water obtained by distillation does not need to be sterilised and is safe to drink.

Suggest why.

Fresh water needs to be sterilised before it is safe to drink.

How is fresh water sterilised?

Tick (✓) two boxes.

A student tests the pH of fresh water using universal indicator solution.

When added to the fresh water, the colour of the universal indicator solution is green.

What is the pH of this fresh water?

This question is about substances used to make windows and window frames.

Figure 2 shows a window.

Glass is made by heating sand with two other materials.

Which two other materials are used to make glass?

Tick (✓) two boxes.

Window frames need to be:

• easy to install

• resistant to damage.

The polymers poly(chloroethene) and HDPE are used to make window frames.

Table 3 shows information about poly(chloroethene) and HDPE.

Suggest one advantage of using poly(chloroethene) compared with HDPE to make window frames.

Give one reason for your answer.

Use Table 3.

Suggest one advantage of using HDPE compared with poly(chloroethene) to make window frames.

Give one reason for your answer.

Use Table 3.

Figure 3 shows the displayed structural formula of poly(chloroethene).

Which monomer is used to make poly(chloroethene)?

Tick (✓) one box.

Chlorine gas is used to produce poly(chloroethene).

Describe a test to identify chlorine gas.

Give the result of the test.

Wood can be used instead of polymers to make window frames.

• Polymers are unreactive.

• Polymers are produced from crude oil.

• Wood breaks down in wet conditions.

• Wood is produced from trees.

Suggest one advantage of using polymers and one advantage of using wood to make window frames.

Advantage of polymers

Advantage of wood

Window frames can also be made from an alloy of aluminium.

6.00 kg of the alloy is used to make a window frame.

Table 4 shows the mass of each element in 6.00 kg of the alloy.

Calculate the percentage of aluminium in 6.00 kg of the alloy.

Why is an alloy used instead of pure aluminium to make window frames?

This question is about reactions between gases.

When hydrogen gas is heated with iodine gas, hydrogen iodide gas is produced.

The equation for this reversible reaction is:

hydrogen + iodine hydrogen iodide

This reversible reaction reaches equilibrium in a sealed container.

How does the equation show that the reaction is reversible?

Which two statements are correct when the reaction reaches equilibrium?

Tick (✓) two boxes.

The initial mixture of hydrogen and iodine in the sealed container is purple.

Hydrogen iodide is colourless.

How will the colour of the mixture in the sealed container have changed when equilibrium is reached?

Tick (✓) one box.

The rate of reaction between gases is affected by changing the pressure.

Complete the sentences.

When the pressure of the reacting gases is increased,

This is because at higher pressures the distance

Give one other way of changing the rate of reaction between gases.

You should not refer to pressure in your answer.

A student investigated the rate of the reaction between zinc and sulfuric acid.

This is the method used.

1. Pour 40 cm³ of sulfuric acid into a conical flask.

2. Add 2.0 g of zinc powder to the conical flask.

3. Put the stopper in the conical flask.

4. Measure the volume of hydrogen gas collected every 30 seconds for 5 minutes.

Figure 4 shows part of the apparatus used.

Figure 4

X shows where a piece of equipment is connected to measure the volume of hydrogen gas collected.

Complete Figure 4 to show the equipment used.

The student made an error setting up the delivery tube shown in Figure 4.

Describe the error and the problem this error would cause.

The student then set up the apparatus correctly.

Figure 5 shows the student’s results.

Complete Figure 5 by drawing a line of best fit.

Determine the mean rate of reaction between 0 seconds and 60 seconds.

Use the equation:

Use data from Figure 5.

Give the unit.

Choose the answer from the box.

The student repeated the investigation using sulfuric acid of a higher concentration.

The student plotted the results and drew a line of best fit.

How would the line of best fit for higher concentration compare with the line of best fit for lower concentration?

Tick (✓) one box.

Potash alum is a chemical compound.

Potash alum contains potassium ions, aluminium ions and sulfate ions.

Which two methods can be used to identify the presence of potassium ions in potash alum solution?

Tick (✓) two boxes.

Sodium hydroxide solution is used to test for some metal ions.

Sodium hydroxide solution is added to a solution of potash alum until a precipitate forms.

Complete the sentence.

Choose the answer from the box.

Complete the sentence.

Choose the answer from the box.

Sulfate ions can be identified using dilute hydrochloric acid

and.

A solution of potash alum has a concentration of 258 g/dm³

Calculate the mass of potash alum needed to make 800 cm³ of a solution of potash alum with a concentration of 258 g/dm³

Give your answer to 3 significant figures.

This question is about organic compounds.

Butane is an alkane with small molecules.

Complete the sentence.

Choose the answer from the box.

Butane can be used as a

Poly(propene) is a polymer.

What is the name of the monomer used to produce poly(propene)?

Tick (✓) one box.

Ethene and steam react to produce ethanol.

The equation for the reversible reaction is:

ethene + steam ethanol

The reaction produces a maximum theoretical mass of 400 kg of ethanol from 243 kg of ethene and 157 kg of steam.

A company produces 380 kg of ethanol from 243 kg of ethene and 157 kg of steam.

The percentage yield of ethanol is less than 100%

Calculate the percentage yield of ethanol.

Use the equation:

What are two possible reasons why the percentage yield of ethanol is less than 100%?

Tick (✓) two boxes.

Ethanol burns in oxygen.

Balance the equation for the reaction.

Two processes for producing ethanol are:

• fermentation

• hydration (reacting ethene with steam).

Table 5 shows information about the processes.

Give two advantages and two disadvantages of using fermentation to produce ethanol.

Advantage of fermentation 1

Advantage of fermentation 2

Disadvantage of fermentation 1

Disadvantage of fermentation 2

This question is about fuels and energy.

Figure 6 shows the percentage of electricity generated in the UK between 2007 and 2017 using:

• oil

• solar energy.

Describe the changes in the percentage of electricity generated in the UK between 2007 and 2017 using:

• oil

• solar energy.

Use data from Figure 6 in your answer.

Oil contains carbon and some sulfur.

When oil is burned, the products of combustion may be released into the atmosphere.

Explain the environmental effects of releasing these products of combustion into the atmosphere.

Suggest one reason why using solar energy is a more sustainable way of generating electricity than burning oil.

Solar energy may not be able to replace the generation of electricity from fossil fuels completely.

Suggest two reasons why.

This question is about alkanes.

Table 6 shows information about some alkanes.

Plot the data from Table 6 on Figure 7.

Predict the boiling point X of the alkane with seven carbon atoms in a molecule.

Use Table 6 and Figure 7.

Figure 7 is not suitable to show the boiling point of the alkane with three carbon atoms in a molecule.

Suggest one reason why.

What is the state at 20 °C of the alkane with four carbon atoms in a molecule?

Use Table 6.

Table 6 is repeated below.

The alkane with nine carbon atoms in a molecule is called nonane.

Complete the formula of nonane.

Nonane will condense lower in a fractionating column during fractional distillation than the other alkanes in Table 6.

Explain why.

You should refer to the temperature gradient in the fractionating column.

This question is about paper chromatography.

A food colouring contains a dye.

Plan an investigation to determine the R_f value for the dye in this food colouring.

Your plan should include the use of:

• a beaker

• a solvent

• chromatography paper.

Two students investigated a dye in a food colouring using paper chromatography.

Each student did the investigation differently.

The R_f values they determined for the same dye were different.

How did the students’ investigations differ?

Tick (✓) one box.

Paper chromatography involves a stationary phase.

What is the stationary phase in paper chromatography?

Tick (✓) one box.