Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Reactivity Series
163 practice questions
Topics covered
- Displacement reactions involving metal oxides20 practice questions
- Oxidation and reduction19 practice questions
- Displacement reactions involving solutions of salts19 practice questions
- Reactions of metals with water18 practice questions
- Reactions of metals with dilute acids19 practice questions
- Making predictions using the reactivity series19 practice questions
- Preventing rusting by galvanising21 practice questions
- Preventing rusting by using sacrificial protection18 practice questions
Practice questions
161–163 of 163
Question 161
7 marks · Hard
Answer and see the solution →Iron structures are often exposed to damp air and water. Two common methods to prevent iron from rusting are galvanising and using sacrificial protection.
(a)[1 mark]State the two conditions necessary for iron to rust.
(b)[2 marks]Describe how galvanising protects iron from rusting. Include what metal is used and how it provides two types of protection.
(c)[2 marks]Ships are often fitted with blocks of magnesium on their steel hulls. Explain how these magnesium blocks protect the iron hull from rusting.
(d)[2 marks]Explain why the iron hull will eventually begin to rust if the magnesium blocks are not replaced.
Question 162
8 marks · Hard
Answer and see the solution →Iron and steel are commonly used in outdoor structures such as bridges and ships. They must be protected from rusting to ensure a long lifespan.
(a)[2 marks]Describe the conditions required for iron to rust. (2 marks)
(b)[2 marks]Explain how galvanising prevents rusting, even if the zinc coating is scratched. (2 marks)
(c)Large steel ships are often protected from rust by attaching blocks of a different metal to their hulls.
(i)[2 marks]State the name given to these blocks and explain their function. (2 marks)
(ii)[2 marks]Give one example of a metal commonly used for this purpose and explain why it is suitable. (2 marks)
Question 163
7 marks · Hard
Answer and see the solution →Iron water tanks and pipelines are often protected from rusting using different methods. One way is to coat the iron with a layer of zinc (galvanising). Another way is to attach a block of a more reactive metal to the iron (sacrificial protection).
(a)[3 marks]Explain how galvanising protects iron from rusting, and why this method is more effective than simply painting the iron.
(b)[4 marks]A buried iron pipeline is protected by attaching solid blocks of a more reactive metal. Using the result of part (a), explain why these 'sacrificial anode' blocks must be replaced regularly. In your answer, explain why the metal used for sacrificial protection must be more reactive than iron.