Advertisements
Advertisements
Question
Why is cooling produced on evaporation of a liquid?
Advertisements
Solution
The evaporation of a liquid requires heat. This heat is taken from the surroundings like the body, palm, forehead, or finger and its temperature falls and we feel cool.
APPEARS IN
RELATED QUESTIONS
Why are we able to sip hot tea or milk faster from a saucer than a cup?
Evaporation takes place from the
Explain why in hot summer days water remains cool in earthen pots.
Why is heat energy needed to melt a solid ? What is this heat energy called ?
During summer days, water kept in an earthen pot (pitcher) becomes cool because of the phenomenon of :
The evaporation of water increases under the following conditions :
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 ?
Comment on the following statements:
Evaporation produces cooling.
Comment on the following statements:
Rate of evaporation of an aqueous solution decreases with increase in humidity.
The rate of evaporation ______ with rising temperature.
