Page 191 - ICSE Chemistry 8

Observa on:
The addi on of copper sulphate to dis lled water converts it to so water. As a result of this, you will
observe the forma on of scum.
You will observe the forma on of lather on the surface of water.

This indicates that the water is so water.

C. Answer in detail.
1. With the help of an ac vity, show that rainwater does not contain any dissolved impuri es but well
water contains them.
2. Explain the water cycle with the help of a diagram.

3. Write a note on the purifi ca on of water.
4. Discuss the physical proper es of water.

5. Write a note on dissolu on of salts in water.
6. With the help of an ac vity, show that copper sulphate crystals contain water of crystallisa on.
7. Write a note on reac vity of metals with water.

8. Discuss how hardness of water can be removed.

OBSERVE AND PERFORM

Observe the given images carefully and answer the following ques ons.

(i) (ii) (iii)

(iv) (v) (vi)

1. Iden fy and name the given sources of water.
2. Categorise these sources under surface water and groundwater.

3. Defi ne water table.
4. How can groundwater be obtained?

177 177