What is meant by ‘rusting’? With labelled diagrams describe an activity to find out the conditions under which iron rusts.
Answers
breakind down
Explanation:
Rusting
Explanation:
Rusting is caused by the oxidation of iron to form Fe2O3. When iron is exposed to damp air for a considerable time, it gets covered with a red-brown flaky substance called rust.
Two essential conditions for rusting are:
- Presence of oxygen.
- Presence of water whose pH is in acidic range.
Experiment to show that rusting of Iron requires both, air and water:
We take three test-tubes and put one clean iron nail in each of the three test-tubes.
In the first test-tube, anhydrous calcium chloride is added to avoid moisture.
In the second test-tube, boiled distilled water is added. Boiled water does not contain any oxygen in it. A layer of oil is put over boiled water in the test-tube to prevent the outside air from mixing with boiled water.
In the third test-tube, unboiled water is added. Two-thirds of nail is immersed in water and the rest is above the water, exposed to damp air.
The mouth of all three test tubes is closed with a cork and it is kept aside for about one week.
After a week, we can observe that rust is seen only in the third test tube and not the other two. This tells us that rusting of iron takes place in the presence of both air and water together.
