Question

Iron can be plated with a layer of zinc to prevent it corroding. This is called galvanising. Explain how galvanising prevents iron from corroding.

Answer 1

Step-by-step explanation:

Galvanizing protects from rust in a number of ways: It forms a barrier that prevents corrosive substances from reaching the underlying steel or iron. The zinc serves as a sacrificial anode so that even if the coating is scratched, the exposed steel will still be protected by the remaining zinc.

Answer 2

Galvanising is a process where iron is coated with a layer of zinc to prevent corrosion. This method is effective because zinc acts as a protective barrier in two key ways:

1. Physical Barrier: The zinc coating serves as a physical barrier, preventing environmental elements like water and oxygen from reaching the iron surface. This is crucial because iron corrodes (rusts) when it comes into contact with oxygen and moisture.
2. Sacrificial Protection: Zinc is more reactive than iron in the electrochemical series. When both metals are exposed to corrosive elements, zinc corrodes (oxidizes) first, sacrificing itself to protect the iron. This means that even if the zinc coating is scratched and the iron underneath is exposed, the surrounding zinc will continue to corrode preferentially, thus safeguarding the iron from rusting.

Galvanising protects iron from corrosion by providing a physical barrier and by offering sacrificial protection through the more reactive nature of zinc.