AQA GCSE Chemistry Paper 2 Foundation June 2023 question paper 8462/2F

This question is about oxygen.

Scientists think that there was little or no oxygen in the Earth’s early atmosphere.

Which planet today has an atmosphere that is similar to the Earth’s early atmosphere?

Tick (✓) one box.

Which is the approximate percentage of oxygen in the Earth’s atmosphere today?

Tick (✓) one box.

Which two of the following increased the percentage of oxygen in the Earth’s atmosphere?

Tick (✓) two boxes.

Some scientists think that 1100 million years ago the Earth’s atmosphere contained:

• 16% oxygen

• 4% carbon dioxide.

Complete Figure 1.

You should:

• complete the y-axis scale

• plot the percentage of oxygen in the Earth’s atmosphere 1100 million years ago.

Oxygen is produced when manganese dioxide is added to hydrogen peroxide solution.

The equation for the reaction is:

hydrogen peroxide → water + oxygen

A student investigated the effect of changing the temperature on the decomposition of hydrogen peroxide.

This is the method used.

1. Add 5 cm³ of hydrogen peroxide solution to three test tubes labelled A, B and C.

2. Place each test tube in a water bath at a different temperature.

3. Add 0.2 g of manganese dioxide to each test tube.

Figure 2 shows the results.

Which test tube contained hydrogen peroxide solution at the highest temperature?

Tick (✓) one box.

The student tested the gas produced.

What is used to prove that the gas is oxygen?

Tick (✓) one box.

Manganese dioxide does not appear in the chemical equation for this reaction.

Which is a correct statement about manganese dioxide in this reaction?

Tick (✓) one box.

This question is about glass and polymers.

Beakers can be made from borosilicate glass or poly(propene).

Table 1 shows information about materials used to make beakers.

Suggest two reasons why a Bunsen burner should not be used to heat a liquid in a poly(propene) beaker.

Use Table 1.

Poly(propene) beakers are more expensive than borosilicate glass beakers.

Suggest one reason why using poly(propene) beakers instead of borosilicate glass beakers could save money.

Use Table 1.

Which is a raw material used to make borosilicate glass?

Tick (✓) one box.

Poly(propene) is produced from propene.

The displayed structural formula of propene is:

Table 2 shows some information about the elements in one molecule of propene.

Complete Table 2.

Which structure is the repeating unit of poly(propene)?

Tick (✓) one box.

Poly(propene) is produced in three stages:

• Stage 1: separating large alkane molecules from crude oil

• Stage 2: producing propene molecules from large alkane molecules

• Stage 3: joining many propene molecules together.

Name Stage 1, Stage 2 and Stage 3.

Choose answers from the box.

Stage 1 is.

Stage 2 is.

Stage 3 is.

A molecule of hexene contains a double carbon–carbon bond.

Many hexene molecules join together to form poly(hexene).

Which two words describe a hexene molecule in this process?

Tick (✓) two boxes.

This question is about chromatography.

A student investigated an orange dye using paper chromatography.

Figure 3 shows the apparatus at the start of the investigation.

Complete the labels on Figure 3.

Figure 4 shows the results at the end of the investigation.

The student made a mistake in the investigation.

What mistake did the student make to produce the results shown in Figure 4 ?

Tick (✓) one box.

A different student did the investigation correctly.

Figure 5 shows the results.

How do the results in Figure 5 show that the orange dye is not a pure substance?

Determine the R_f value for the red spot.

You should measure:

• the distance moved by the red spot

• the distance moved by the solvent.

Use Figure 5 and the equation:

distance moved by red spot R = distance moved by solvent

Which spot had the greatest R_f value?

Use Figure 5.

Tick (✓) one box.

This question is about a reversible reaction.

A student heated calcium hydroxide to produce calcium oxide and water vapour.

This is the method used.

1. Add 2.00 g of calcium hydroxide into a test tube.

2. Heat the test tube and contents for 1 minute using a Bunsen burner.

3. Allow the test tube and contents to cool.

4. Weigh the test tube and contents.

5. Repeat steps 2 to 4 five more times.

Table 3 gives the appearance of the reactant and of the products.

The student looked at the test tube and contents during heating.

The student could not tell that a chemical reaction was taking place by looking at the test tube and contents.

Give two reasons why.

Use the information in Table 3.

Accurate results are not produced if solid powders escape from the test tube during heating.

Suggest why sealing the test tube with a stopper is not a good way of preventing the solid powders from escaping.

The student wanted to calculate the mass of the contents of the test tube after each minute of heating.

The student weighed the test tube and contents after each minute of heating.

What other measurement is also needed to calculate the mass of the contents of the test tube?

Tick (✓) one box.

The student heated 2.00 g of calcium hydroxide to produce calcium oxide and water vapour.

Table 4 shows the results.

Complete the sentence.

Choose the answer from the box.

Use Table 4.

The minimum heating time needed for all of the calcium hydroxide to be changed into

Calculate the total mass of water vapour produced by heating the calcium hydroxide.

Use Table 4.

The word equation for the reaction is:

calcium hydroxide calcium oxide + water

The reaction is reversible.

When 4.00 g of calcium hydroxide is completely changed into calcium oxide and water:

• 3.03 g of calcium oxide is produced

• 5.90 kJ of energy is taken in from the surroundings.

3.03 g of calcium oxide reacts completely with water to produce 4.00 g of calcium hydroxide.

How much energy is transferred to the surroundings in this reaction?

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The forward reaction takes in energy from the surroundings.

Complete the sentence.

Choose the answer from the box.

The forward reaction is.

This question is about greenhouse gases and climate change.

Which two gases are greenhouse gases?

Tick (✓) two boxes.

Why are greenhouse gases essential for supporting life on Earth?

The percentage of greenhouse gases in the Earth’s atmosphere today is increasing.

Many scientists think that this increase is causing global climate change.

What is a cause of the greenhouse effect?

Complete the sentence.

Greenhouse gases absorb long wavelength

Which two are potential effects of global climate change?

Tick (✓) two boxes.

Water vapour is a greenhouse gas.

The percentage by mass of water vapour in the Earth’s atmosphere is 0.25%.

Calculate the mass of water vapour in 350 kg of the Earth’s atmosphere.

Give your answer in grams.

This question is about fuels.

The energy produced by burning fuels is used to generate electricity in power stations.

Table 5 shows information about three fuels used to generate electricity.

Explain why coal is usually transported to power stations by train and not by pipeline.

Use Table 5.

Sulfur dioxide and particulates are atmospheric pollutants produced when fuels are burned.

1 kg of each fuel in Table 5 is burned.

Which fuel produces the most sulfur dioxide?

Give one reason for your choice.

Give one problem caused by sulfur dioxide.

Particulates are formed from solid particles.

1 kg of each fuel in Table 5 is burned.

Which fuel produces the least particulates?

Give one reason for your choice.

Give one problem caused by particulates.

Complete the sentence.

Figure 6 shows how the use of oil and of natural gas as fuels changed in the UK between 2002 and 2020.

Describe the trends shown in Figure 6.

This question is about alloys.

Steels are alloys of iron.

Which non-metal element is in all steels?

Tick (✓) one box.

Which two elements other than iron are in stainless steels?

Tick (✓) two boxes.

Give two properties of stainless steels.

Choose answers from the box.

Titanium is used in alloys.

Table 6 shows information about some alloys of titanium.

Calculate the mass of titanium in 5.0 kg of titanium alloy C.

Use Table 6.

Suggest why alloy A and alloy B are used to make aircraft parts.

Use Table 6.

Titanium alloys used for medical purposes must not be toxic.

Suggest why alloy B is not used for medical purposes.

Use Table 6.

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

Hydrogen gas is produced during this reaction.

Figure 7 shows the apparatus.

This is the method used.

1. Add 50 cm³ of sulfuric acid to a conical flask.

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

3. Quickly put a stopper in the conical flask and start a timer.

4. Measure the time taken to collect 20 cm³ of gas.

5. Repeat steps 1 to 4 three more times.

Suggest why the stopper must be put in the conical flask as quickly as possible in step 3.

The student calculated the rate of the reaction for each trial.

Table 7 shows the results of the calculations.

Determine the mean time taken to collect 20 cm³ of gas.

Do not include any anomalous results.

Use the equation:

The student changed the investigation so that the mean time taken to collect 20 cm³ of gas was greater.

Which two changes would increase the mean time taken to collect 20 cm³ of gas?

Tick (✓) two boxes.

Hydrogen gas is produced during this reaction.

Describe the test for hydrogen gas.

Give the result of the test.

This question is about alcohols and carboxylic acids.

Alcohols are used as fuels.

A student burned 1.00 g of six alcohols and determined the energy released from each.

Table 8 shows the results.

Calculate the mass of ethanol that must be burned to release the same amount of energy as burning 1.00 g of heptanol.

The energy released in kJ/g varies with the number of carbon atoms in one molecule of each alcohol.

Plot the data from Table 8 on Figure 8.

Estimate the energy released in kJ when 1.00 g of octanol (C₈H₁₇OH) is burned.

Use Figure 8.

Carbon dioxide is produced when alcohols are burned.

Carbon dioxide is identified by bubbling the gas through limewater.

Complete the sentence.

Choose the answer from the box.

Limewater is an aqueous solution of

Give the result of the test when carbon dioxide is bubbled through limewater.

Ethanoic acid can be produced from ethanol.

What is reacted with ethanol to produce ethanoic acid?

Tick (✓) one box.

Ethanoic acid contains the functional group –COOH

Complete the displayed structural formula of this functional group.

Ethanoic acid reacts with different compounds.

Draw one line from each compound to a product of the reaction of the compound with ethanoic acid.

Product of the reaction

This question is about chemical analysis.

Potassium bromide is used in medicine.

A scientist tested a sample of medicine to show the presence of potassium ions and of bromide ions.

The sample is soluble in water.

Plan a method the scientist could use to show that the sample of medicine contains potassium ions and bromide ions.

The scientist has:

• a Bunsen burner

• a metal wire

• test tubes

• a dropping pipette

• distilled water

• dilute nitric acid

• silver nitrate solution.

You should give the results of the tests.

The scientist could also use an instrumental method to show the presence of potassium ions in the medicine.

Which instrumental method could be used to show the presence of potassium ions in the medicine?

Give one advantage of using this instrumental method instead of a chemical test.