Suggest an experiment to prove that the presence of air and water an essential for corrosion. Explain the procedure.

An experiment to prove that the presence of air and water are essential for corrosion is:-

Materials required:

Three test tubes, three iron nails, oil, water, anhydrous calcium chloride, rubber corks.

Procedure to follow : -

a. In the first step take 3 test tubes and place clean iron nails in each of them. Label the test tubes as A, B and C.

b. Pour some water in test tube A and cork it up.

c. Pour boiled distilled water in test tube B, and add about 1ml of oil and cork it up also.

d. Put some anhydrous calcium chloride in test tube C and cork it.

e. Leave these test tubes for a few days and then observe the nails.

f. It would be observed that the nails in test tube A and B would have rusted but not the nails in the test tube C.

Explanation –

a. In test tube A, the nails are being exposed to air and water. Hence the nails rusted.

b. In the test tube B, the nails are only being subjected to the water as the oil cancelled the exposure to air. Hence, the nails are also rusted here.

c. In test tube C the nail is only being exposed to dry conditions because the anhydrous Calcium Chlorate present had absorbed any moisture if present in the test tube. Hence, here the nails had not rusted due to the absence of air and water.

Hence from the above experiment we can conclude that air and water are essential for corrosion.

Explanatory Diagram