Question

Write the activity that shows the conditions necessary for corrosion.

Answer 1

Answer:

Explanation:

Rusting of iron: It is oxidation of iron by oxygen and water. Thus presence of moisture in air is cause of rusting.

General equation:

4Fe + 3O2 + 2xH2O → 2Fe2O3.xH2O

Activity-

1) Place two iron nails in test tube A with some white anhydrous calcium chloride solid. The top of test tube plugged with some cotton. Calcium chloride absorbs water vapors from the air and so the air is dry- water is not present.

2) Place two iron nails in a stoppered test tube B of boiled water with a layer of oil drop on the top of the water. The water was boiled for 15 minutes to drive off all the dissolved oxygen. The oil prevents from the air dissolving in the water.

3) Place two iron nails in test tube C containing some water.

4) Allow the test tubes to stand in a beaker for few days and examine rusting.

Result- Rusting occurs in two iron nails present in test tube C

Conclusion- water and oxygen are together needed for rusting