Question

Describe in brief an activity to investigate the conditions under which an article made of iron rusts. List any four methods used for the prevention of rusting of iron.

Answer 1

Activity:

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

2. Label these 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 1 mL 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. Leave these test tubes for a few days and then observe.

Diagram:

Observation:

Iron nails rust in test tube A, but they do not rust in test tubes B and C. In the test tube A, the nails are exposed to both air and water. In the test tube B, the nails are exposed to only water, and the nails in test tube C are exposed to dry air.

Conclusion:

Moist air and water are required for rusting to take place.

Methods for the prevention of rusting are:

1. Painting

2. Oiling/greasing

3. Galvanizing

4. Chrome painting

5. Anodizing