Question

State the reason why zinc is used in the galvanisation of iron and not copper.

Answer 1

• More reactive metal is galvanized over less reactive metal.
• Zinc being more reactive than iron is used to galvanize and protect iron from corrosion by forming a very dense and impermeable coating of zinc oxide when oxygen in the air reacts with the surface of zinc, and it is this physical barrier that protects the iron surface from further attack.
• Copper being a less reactive metal cannot displace iron and go on to form a separate layer. Therefore it is not used for galvanization.