NCERT Activity 3.14 Class 10 Science Explanation | Metals and Non-Metals Activity 3.14

In this activity, we will learn about the conditions responsible for the rusting of iron.

Aim

To find the conditions that are responsible for rusting

 

Materials Required

   1.  Three iron nails

   2. Three test tubes

   3. Corks

   4. Boiled distilled water

   5.  Oil

   6.  Anhydrous calcium chloride

   7. Test tube stand

Procedure

We take three clean test tubes and place one iron nail in each. Now we label them as A, B, and C.

We pour tap water into test tube A until the nail is partially immersed and cork the tube.

We pour boiled distilled water until the nail is partially immersed and add 1 ml of oil, and cork it tightly.

Finally, we place a few pellets of anhydrous calcium chloride in test tube C along with a nail.

Now we leave all the test tubes for a few days and then observe.

Observation

 It is observed that iron nails rust in test tube A, but they do not rust in test tubes B and C. In test tube A, the nails are exposed to both air and water. In test tube B, the nails are exposed to water only, and the nails in test tube C are exposed to dry air free from water vapour.

Explanation

Rusting of iron requires both oxygen (air) and water (moisture). So, in the test tube A, both are present.

Chemical Reaction of Rusting of Iron

4Fe + 3O₂ + xH₂O →2Fe₂O₃.xH₂O

Conclusion

We can conclude that the Presence of both air and moisture is essential for rusting to take place. In test tube A, both air and water are present; in test tube B, there is no air dissolved in the water, and in test tube C, the air is dry.

Frequently Asked Questions

   1. Why is boiled water used in test tube B?

Answer – To remove dissolved oxygen from water.

   2. Why is oil added to test tube B?

Answer – A Layer of oil prevents oxygen from dissolving in water and coming into contact with the nail.

   3. Why is anhydrous calcium chloride used in test tube C?

Answer – Anhydrous CaCl₂ absorbs moisture from the air and creates a dry environment.

   4. What are the necessary conditions for the rusting of iron?

Answer – The Presence of both oxygen and moisture is necessary for the rusting of iron.