Describe an activity to show that the rusting of iron occurs in the presence of air and moisture.

Explanation

(i) Take three test-tubes. Place clean iron nails ineach test-tube.
(ii) Pour some water in test-tube -1, cork it.
(iii) Pour water (boiled/distilled) in test-tube-2, add some oil and cork it.
(iv) Put some anhydrous calcium chloride in test-tube-3 and cork it.
(v) After 2-3 days, we observe that the nails in test-tube 1 trust because they are exposed to air and water both, while nail in test-tube 2 and 3 do not rust. This shows that rusting of iron takes place in the presence of air and moisture both.