A river water sample is poured in four containers and subjected to four different processes as shown in the following diagram. Answer the following questions by analysing the given diagram (a) Which water is the most suitable for cinsumption? (b) What are the disadvantage of other water samples? (c ) What happens when fish are placed in the containers A, B, C and D?

A river water sample is poured in four containers and subjected to fou

1.	A river water sample is poured in four containers and subjected to four different processes as shown in the following diagram. Answer the following questions by analysing the given diagram (a) Which water is the most suitable for cinsumption? (b) What are the disadvantage of other water samples? (c ) What happens when fish are placed in the containers A, B, C and D?
Answer» (a) Water in container D is the safest one for consumption as ozone kills the disease- causing germs and bacteria. The water is devoid of both suspended impurities as well as microorganisms. (b) (i) Water in container A is devoid of sus- pended impurities, but contains the germs and bacteria. Consumption of this water may lead to a number of water borne diseases. (ii) Sample 13 - Filtration removes all sus- pended impurities. Boiling to some extent kills the germs and bacteria. But, this water is devoid of dissolved gases and has insipid taste. (iii) Sample C- The water sample is distilled water. This is devoid of dissolved gases. This is not fit for consumption. (c ) Fish die when they are kept in containers B or C because the water does not contain dissolved oxygen required for the respiration of fishes.