Question

why zinc is used in galvanising

Answer 1

To protect iron and steel from rusting

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Answer 2

Galvanisation is a method of protecting steel and iron from rusting by coating them with a thing layer of zinc. The galvanised article is protected against rusting even if the zinc coating is broken because Zinc is more reactive than iron, it is used to protect it from corrosion because when oxygen in the air reacts with the surface of zinc, a very dense and impermeable coating of zinc oxide is formed and it is this physical barrier that protects the zinc surface from further attack.

Or in simple words

Since zinc is more reactive than iron, when we galvanize iron with zinc, zinc react with oxygen to form a thin layer of oxide which prevents metal to further corrosion.

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