Question

Why is zinc better than sn in protecting iron from corrosion?

Answer 1

Zinc is more reactive than Fe. Hence, if zinc coated iron comes in contact with any corrosive materials the zinc layer is more likely to be corroded than the iron beneath. However tin is less reactive than Fe. Hence even if a small scratch exposes Fe to corrosive materials it can lead to the corrosion of the entire iron beneath the tin as Fe is more likely to be corroded than tin.

Answer 2

Coating by zinc is better to protectmetal from corrosion. This is because, on coating the metal by zinc, it acts as physical barrier and protects the metal from environment. ... Thus it furtherprotects from corrosion. Outer portion of zinc coating reacts with oxygen, moisture and carbon dioxide to formzinc carbonate.