LAB ACTIVITY CLASS X Factors Affecting Corrosion

FACTORS OF RUSTING IRON.

Aim: To observe the factors of rusting iron.

Required material: Test tubes -3, rubber corks, iron nails 9, distilled water, oil, calcium chloride.

Principle: In the presence of water and air iron changes its colour as brown. This phenomenon is called rusting.

Procedure:

1) Take three test tubes and place clean iron nails in each of them.

2) Label the test tubes A, B and C. Pour some water in test tube “A” and cork it.

3) Pour boiled distilled water in test tube “B” ,add about 1ml of oil and cork it. The oil will float on water and prevent the air from dissolving in the water.

4) Put some anhydrous calcium chloride in test tube “C” and cork it. Anhydrous calcium chloride will absorb the moisture, if any from the air.

5) Leave the test tubes for a few days.

Observations:

1)We observe that the iron nails rust in test tube “A”.

2)They do not rust in test tube “B” and “C”.

3)In test tube “A” the nails are exposed to both air and water.

4)In test tube “B” the nails are exposed to only water.

5)The nails in the test tube “C” are exposed to dry air.

Result: Corrosion (Rusting of iron)

occurs in presence of water and air.

Precautions : watch the nails in the test

tubes regularly. We must use only clean iron

nails.