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Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit

Inorganic Chemistry

869 practice questions

Topics covered

Practice questions

351–359 of 359 · Easy

  1. Question 351

    5 marks · Easy

    A student tests a colorless liquid. She wants to find out whether it is pure water or contains dissolved chloride ions from an unknown salt. She also has some ammonia solution for use in any tests required.

    (a)

    Describe how the student could use a chemical test to show whether the liquid contains water, and explain what her result would mean about the presence of water.

    [1 mark]
    (b)

    The student measures the boiling point of the liquid and finds it to be 102°C (at 1 atmosphere pressure). Calculate the difference between this boiling point and the boiling point of pure water under these conditions, and explain what this result shows about the purity of the liquid.

    [2 marks]
    (c)

    To test for dissolved chloride ions, the student adds dilute nitric acid, followed by silver nitrate solution. She obtains a white precipitate. Explain why it is important to add the nitric acid before the silver nitrate solution in this test.

    [2 marks]
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  2. Question 352

    5 marks · Easy

    Two unknown solutions, labelled X and Y, are tested. Solution X gives off a gas when warmed with sodium hydroxide. Solution Y forms a precipitate when tested with silver nitrate and dilute nitric acid.

    (a)

    State the name of the gas given off by X when warmed with sodium hydroxide, and describe how you would test for it (including the result expected).

    [2 marks]
    (b)

    Solution Y gives a yellow precipitate when tested with silver nitrate and dilute nitric acid. State which ion is present in Y, and the name and colour of the precipitate formed.

    [2 marks]
    (c)

    Describe how you could distinguish between the precipitates formed with chloride and iodide ions using this test.

    [1 mark]
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  3. Question 353

    7 marks · Easy

    This question is about determining the amount of oxygen in air and key ideas about oxidation and reduction.

    (a)

    Describe how copper metal can be used to determine the percentage of oxygen in air, including the main observations and calculation.

    [3 marks]
    (b)

    Explain why copper must be in excess in this experiment.

    [1 mark]
    (c)

    Define what is meant by 'oxidising agent' and 'reducing agent' in a chemical reaction.

    [2 marks]
    (d)

    State which substance is the oxidising agent when magnesium reacts with copper(II) oxide, and briefly justify your answer.

    [1 mark]
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  4. Question 354

    7 marks · Easy

    You will use combustion and displacement to answer the following questions.

    (a)

    A student combusts magnesium in pure oxygen and collects 4.8 g of magnesium oxide as product. Write a balanced equation for this reaction.

    [1 mark]
    (b)

    Calculate the minimum mass of magnesium that could have reacted to produce 4.8 g of magnesium oxide (MgO). [Mg = 24, O = 16]

    [2 marks]
    (c)

    If the products from part (a) are mixed with copper(II) oxide and heated, a reaction occurs. Write an equation for the displacement reaction.

    [1 mark]
    (d)

    State which metal is reduced in this reaction, and explain your answer.

    [1 mark]
    (e)

    Calculate the maximum mass of copper that can be formed if 4.8 g of MgO (from part (a)) originally came from enough Mg, and all the Mg is used to displace copper from CuO. [Cu = 64]

    [2 marks]
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  5. Question 355

    7 marks · Easy

    This question requires you to use knowledge of oxides formed by combustion and oxidation/reduction principles.

    (a)

    State whether the oxide formed when sulfur burns in oxygen is acidic or basic, and give a reason.

    [2 marks]
    (b)

    When magnesium burns in oxygen, what type of oxide is formed? How does it behave in water?

    [2 marks]
    (c)

    For the reaction: Zn(s) + CuO(s) → ZnO(s) + Cu(s) Explain in terms of oxygen transfer which substance is oxidised and which is reduced.

    [2 marks]
    (d)

    Give the definition of oxidation in terms of electron transfer, and state which substance is oxidised in the reaction in (c).

    [1 mark]
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  6. Question 356

    7 marks · Easy

    Answer the questions about greenhouse gases and redox agents.

    (a)

    State what is meant by a 'greenhouse gas' and name one greenhouse gas present in the Earth’s atmosphere.

    [2 marks]
    (b)

    Explain how carbon dioxide is released into the atmosphere during the combustion of fossil fuels.

    [1 mark]
    (c)

    Describe one possible environmental impact caused by an increase in greenhouse gases such as carbon dioxide.

    [1 mark]
    (d)

    In the following reaction, identify the oxidising agent and explain your answer in terms of oxygen transfer: Mg(s) + CuO(s) → MgO(s) + Cu(s)

    [2 marks]
    (e)

    Suggest why carbon dioxide is not removed from the atmosphere as quickly as it is added by combustion.

    [1 mark]
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  7. Question 357

    7 marks · Easy

    This question is about carbon dioxide and redox reactions.

    (a)

    Write the word equation and the balanced symbol equation for the thermal decomposition of copper(II) carbonate.

    [2 marks]
    (b)

    State the products formed when copper(II) carbonate is heated.

    [1 mark]
    (c)

    Explain, in terms of electron transfer, which substance is reduced in the extraction of copper from copper(II) oxide using carbon.

    [2 marks]
    (d)

    Write the half-equation for the reduction of copper(II) ions to copper atoms.

    [1 mark]
    (e)

    Identify the reducing agent in the reaction between copper(II) oxide and carbon and explain your answer.

    [1 mark]
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  8. Question 358

    7 marks · Easy

    This question is about the composition of air and displacement reactions.

    (a)

    State the approximate percentage by volume of oxygen in dry air.

    [1 mark]
    (b)

    A student heated zinc with copper(II) oxide and collected the following data: - Mass of zinc used: 0.15 g - Mass of copper(II) oxide used: 0.80 g - Mass of copper formed: 0.50 g Calculate the maximum mass of copper that can be obtained. (Relative atomic masses: Zn = 65, Cu = 63.5, O = 16)

    [3 marks]
    (c)

    Write the ionic equation (with state symbols) for the displacement reaction between zinc and copper(II) ions in solution.

    [1 mark]
    (d)

    Explain which substance is reduced in this reaction.

    [2 marks]
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  9. Question 359

    7 marks · Easy

    This question is about methods for showing the percentage of oxygen in air and spectator ions in displacement reactions.

    (a)

    Describe one method for measuring the percentage of oxygen in air, including the apparatus used and the main steps.

    [3 marks]
    (b)

    A student adds iron filings to copper(II) sulfate solution. Write the full word equation for this reaction and explain what is observed.

    [2 marks]
    (c)

    Write the full ionic equation for the reaction and identify the spectator ions.

    [2 marks]
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