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Comment on the following statements. (...

Comment on the following statements.
(a) Evaporation produces cooling.
(b) Rate of evaporation of an aqueous solution decreases with increases with increase in humidity .
(c) Sponge though compressible is a solid.

Text Solution

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(a) As a liquid changes into vapours during evaporation, it needs some energy which it takes from the surroundings. Since the temperature of the surroundings gets lowered, cooling is therefore, caused.
(b) Increase in humidity results in increase in moisture in the atmosphere. As a result, water has less tendency to change into the vapours and rate of evaporation decreases.
(c ) Sponge is basically a solid. However, it has very fine holes which are called pin holes. Air gets trapped in these holes and the size of the sponge somewhat increases. On compressing, air escapes from the pores or holes and the size of the sponge decreses.
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