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

Inorganic Chemistry

869 practice questions

Topics covered

Practice questions

161–170 of 359 · Easy

  1. Question 161

    3 marks · Easy

    An iron bridge over a river is being considered for galvanising to prevent rusting.

    (a)

    Describe the process of galvanising.

    [1 mark]
    (b)

    State how galvanising protects the iron bridge from rusting.

    [2 marks]
    Answer and see the solution →
  2. Question 162

    2 marks · Easy

    A steel railing has a surface area of 400 cm² and is to be protected from rusting by covering it with a thin layer of zinc (galvanising). If 0.15 g of zinc is needed to cover 100 cm², calculate the minimum mass of zinc needed to fully galvanise the railing. Give your answer to 2 decimal places.

    Answer and see the solution →
  3. Question 163

    2 marks · Easy

    A metal sheet weighing 1.2 kg is coated by galvanising to prevent rusting. The layer of zinc adds 0.006 kg to its mass. Calculate the percentage increase in mass of the sheet after galvanising. Give your answer as a percentage to two decimal places.

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  4. Question 164

    1 mark · Easy

    State one example of a structure that is protected from rusting using sacrificial anodes.

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  5. Question 165

    3 marks · Easy

    Iron pipes used in water supply networks are often fitted with zinc blocks to prevent rusting.

    (a)

    Describe what happens to the zinc block over time.

    [1 mark]
    (b)

    Explain how the zinc block prevents the iron pipe from rusting.

    [2 marks]
    Answer and see the solution →
  6. Question 166

    2 marks · Easy

    A large storage tank for water is made of steel and is buried underground. Magnesium blocks are attached to its surface.

    Explain why magnesium is a suitable choice to protect the tank and suggest one other metal that could be used for this purpose.

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  7. Question 167

    3 marks · Easy

    The table shows how the mass of a zinc sacrificial anode attached to an iron structure changes over four years.

    YearMass of zinc anode (g)
    0500
    1425
    2355
    3295
    4240
    (a)

    State the decrease in mass of the zinc anode during the second year (from year 1 to year 2).

    [1 mark]
    (b)

    Explain why the zinc anode loses mass over time.

    [1 mark]
    (c)

    Describe how this process protects the iron structure from rusting.

    [1 mark]
    Answer and see the solution →
  8. Question 168

    1 mark · Easy

    State why a sacrificial anode used to protect iron must be more reactive than iron.

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  9. Question 169

    3 marks · Easy

    Some large steel structures are fitted with blocks of magnesium for protection.

    (a)

    State what these magnesium blocks are called.

    [1 mark]
    (b)

    Describe how these magnesium blocks help prevent the steel structure from rusting.

    [2 marks]
    Answer and see the solution →
  10. Question 170

    2 marks · Easy

    An iron water tank is protected from rust by a zinc block acting as a sacrificial anode. Over 24 months, the mass of the zinc block decreases from 800 g to 620 g.

    Calculate the average mass of zinc lost per month. Show your working.

    Answer and see the solution →