Advertisements
Advertisements
प्रश्न
Why is cooling produced on evaporation of a liquid?
Advertisements
उत्तर
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
संबंधित प्रश्न
Evaporation takes place from the
State three factors which affect the rate of evaporation of a liquid.
Why are volatile liquids such as alcohol and spirit stored in tightly closed bottles?
Explain with an example to demonstrates that when a liquid evaporates, it takes heat from its surroundings.
Explain why in hot summer days water remains cool in earthen pots.
How can the evaporation of a liquid be made faster ?
Why does evaporation cool a liquid ?
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 ?
Look at Fig. 1.3 and suggest in which of the vessels A,B, C or D the rate of evaporation will be the highest? Explain.
The rate of evaporation ______ with rising temperature.
