Question

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

Answer 1

This is because on coating the metal by zinc it acts as physical barrier and protect metal from enviorment . this further protects from corrosion outer portion of zinc coating reacts with oxygen moister and carbondioxide to for zinc carbonate..

Answer 2

Zinc Serves as a Sacrificial Coating. Interestingly, another reason that zinc coating is so effective at stopping corrosion is due to zinc's own corrosive properties. Through a process known as galvanic corrosion, zinc will “defer” to the metal that it's protecting. Zinc is more electrochemically active than iron.