Question

(a) Why is an iron grill painted frequently ?

(b) Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.

Answer 1

(a) An iron grill is painted frequently to prevent its rusting .

(b)There is less corrosion of aluminium than iron when both are exposed to air because aluminium forms a layer of aluminium oxide on its surface as soon as it comes in contact with moist air. This aluminium oxide is very tough and prevents it from corroding right through.