Zn is more electropositive than Fe. Therefore, it should get corroded faster than Fe. But it does not happen. Instead, it is used to galvanize iron. Explain why does it happen so?

Though zinc is more reactive than iron but when a layer of zinc is exposed to the atmosphere zinc reacts with the oxygen in the atmosphere to form zinc oxide. This zinc oxide forms a protective layer on the surface of zinc which prevents the further attack. Hence zinc is used to galvanize iron.