Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Preventing rusting by galvanising
21 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →State the two conditions necessary for iron to rust. Explain why covering iron with zinc prevents rusting, even if the zinc layer is scratched.
Question 2
5 marks · Hard
Answer and see the solution →The diagram shows an iron pipe exposed outdoors. The owner wants to protect it from rusting using galvanising.
(a)[2 marks]Describe the process of galvanising as a method of preventing rusting.
(b)[2 marks]Explain why the pipe does not rust even if the zinc coating is damaged in places.
(c)[1 mark]State one other method, apart from galvanising, that could be used to prevent the pipe from rusting, and explain how it works.
Question 3
2 marks · Hard
Answer and see the solution →A steel beam is coated with zinc to prevent rusting. Explain why salty water increases the rate of rusting if the zinc coating is damaged.