Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Preventing rusting by galvanising
21 practice questions
Practice questions
1–8 of 8 · Easy
Question 1
1 mark · Easy
Answer and see the solution →State what forms on iron when it rusts.
Question 2
3 marks · Easy
Answer and see the solution →The picture below shows a steel fence post that has rusted at the base after several years in a damp garden.
(a)[2 marks]State two conditions necessary for rusting to occur on the steel post.
(b)[1 mark]Name one method, other than painting, which could have prevented rusting of the steel post.
Question 3
2 marks · Easy
Answer and see the solution →Explain why galvanising is able to protect iron from rusting even when the zinc coating is scratched.
Question 4
3 marks · Easy
Answer and see the solution →The table below shows the results of an experiment. Three identical iron nails were placed under different conditions for 10 days to investigate rusting.
Rusting of iron nails under different conditions. Test tube Conditions Rust formed after 10 days? 1 Air only No 2 Water only (boiled, air excluded) No 3 Air and water Yes (a)[1 mark]Which test tube shows the conditions needed for rusting?
(b)[2 marks]Explain why no rust formed in test tube 2.
Question 5
1 mark · Easy
Answer and see the solution →State one reason why coating iron with oil or grease helps prevent rusting.
Question 6
3 marks · Easy
Answer and see the solution →An iron bridge over a river is being considered for galvanising to prevent rusting.
(a)[1 mark]Describe the process of galvanising.
(b)[2 marks]State how galvanising protects the iron bridge from rusting.
Question 7
2 marks · Easy
Answer and see the solution →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.
Question 8
2 marks · Easy
Answer and see the solution →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.