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

Principles of Chemistry

991 practice questions

Topics covered

Practice questions

941–950 of 991

  1. Question 941

    2 marks · Hard

    An aqueous solution of zinc sulfate is electrolysed using inert electrodes.

    State whether hydrogen or zinc is produced at the cathode. Explain your answer using the reactivity series.

    Answer and see the solution →
  2. Question 942

    5 marks · Hard

    A student electrolyses separate aqueous solutions containing different anions using inert electrodes.

    (a)

    State which ion produces oxygen gas at the anode when an aqueous solution of sodium sulfate is electrolysed.

    [1 mark]
    (b)

    Explain why oxygen is produced at the anode during this electrolysis and not another gas.

    [2 marks]
    (c)

    During the electrolysis of aqueous sodium chloride with inert electrodes, state the product formed at the anode. Explain your answer.

    [2 marks]
    Answer and see the solution →
  3. Question 943

    2 marks · Hard

    Predict the products formed at the electrodes when an aqueous solution of copper(II) bromide is electrolysed using inert electrodes.

    State the product formed at:

    (a)

    the cathode

    [1 mark]
    (b)

    the anode

    [1 mark]
    Answer and see the solution →
  4. Question 944

    1 mark · Easy

    State what you would observe if you tested solid sucrose (sugar) for electrical conductivity using an electric circuit with a bulb.

    Answer and see the solution →
  5. Question 945

    3 marks · Easy

    A student investigates the conductivity of three white solids: sodium chloride, glucose, and wax. She sets up the following experiment:

    Series circuit: cell, lamp, wire
    Simple circuit for testing conductivity of solids
    (a)

    Sodium chloride does not conduct electricity as a solid, but the bulb lights up when it is dissolved in water. What does this indicate about sodium chloride?

    [1 mark]
    (b)

    Glucose does not conduct electricity, whether solid or dissolved in water. What type of substance is glucose?

    [1 mark]
    (c)

    Wax does not conduct electricity as a solid or when melted. What does this suggest about wax?

    [1 mark]
    Answer and see the solution →
  6. Question 946

    2 marks · Easy

    Explain why sodium chloride conducts electricity when molten, but not as a solid.

    Answer and see the solution →
  7. Question 947

    3 marks · Easy

    A student tests three substances for their ability to conduct electricity when solid and when dissolved in water. The results are shown in the table.

    Conductivity results
    SubstanceConducts as a solid?Conducts dissolved in water?
    A (potassium bromide)NoYes
    B (ethanol)NoNo
    C (magnesium)Yesn/a
    (a)

    Identify substances A, B, and C as ionic, covalent, or metallic.

    [2 marks]
    (b)

    Which substance is a non-electrolyte?

    [1 mark]
    Answer and see the solution →
  8. Question 948

    1 mark · Easy

    Name a common non-electrolyte used in food and explain why it does not conduct electricity.

    Answer and see the solution →
  9. Question 949

    3 marks · Easy

    The table gives the results for the electrical conductivity of three substances in different states:

    Conductivity results for different substances
    SubstanceSolidMoltenAqueous
    DNoYesYes
    ENoNoNo
    FYesYesn/a
    (a)

    Which substance is a non-electrolyte? Explain your answer.

    [1 mark]
    (b)

    What type of bonding does substance D have? Explain using the data.

    [1 mark]
    (c)

    State the bonding present in substance F.

    [1 mark]
    Answer and see the solution →
  10. Question 950

    2 marks · Easy

    A student tests solid sodium chloride and sugar for electrical conductivity. She finds that only molten sodium chloride conducts electricity, while sugar does not conduct electricity when molten or in solution.

    State, with a reason, whether each substance is ionic, covalent, or a non-electrolyte.

    (a)

    Sodium chloride:

    [1 mark]
    (b)

    Sugar:

    [1 mark]
    Answer and see the solution →