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प्रश्न
Why does evaporation cool a liquid ?
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उत्तर
Evaporation cools the surroundings and the rest of the liquid because when a liquid evaporates, it takes up the latent heat of vaporisation from the surroundings and the rest of the liquid present below the surface with which, it is in contact.
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संबंधित प्रश्न
Why are we able to sip hot tea or milk faster from a saucer than a cup?
Why are volatile liquids such as alcohol and spirit stored in tightly closed bottles?
How does the water kept in an earthen pot (matka) become cold during summer ?
The scientists now say that there are actually five states of matter A, B, C, D and E. The state A has a fixed volume but no fixed shape. The state B can be compressed very easily by applying pressure and state C has a fixed shape as well as a fixed volume. The state D is a mixture of free electrons and ions whereas state E is named after an Indian scientist and a famous physicist.
- Name the physical states (i) A (ii) B (iii) C (iv) D, and (v) E
- Name one substance belonging to state C which can directly change into vapours on heating. What is this process known as ?
- Name one substance which normally belongs to state B but whose solid form changes directly into gaseous state.
- Name the most common substance belonging to state A.
- Which state of matter makes the sun and other stars to glow ?
The ______ of air is dependent on the temperature of air.
Comment on the following statements:
Rate of evaporation of an aqueous solution decreases with increase in humidity.
The rate of evaporation ______ with rising temperature.
The rate of evaporation is more when the surface area is greater.
When lemon juice is mixed with soda water, they produce brisk effervescence.
The process of evaporation is not a good technic to separate salt from seawater give a reason.
