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प्रश्न
What is boiling? Explain it on the basis of molecular motion?
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उत्तर
BOILING: “The change of liquid to vapours on heating at a constant temperature is called BOILING”
K.E = `1/2`Mv2: more the speed of molecules more is the kinetic energy. Heating of the liquid increases the average kinetic energy of liquid molecules and molecules acquire sufficient K.E. needed to overcome the force of attraction of other molecules. These molecules start leaving the liquid not only at the surface but also near the walls of the containing vessel and bubbles are seen on the walls of the vessel. This causes the agitation in the whole of the liquid and this is called boiling.
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संबंधित प्रश्न
Evaporation takes place only from the surface of liquid.
Temperature of a liquid rises during boiling or vaporization
All molecules of a liquid take part in boiling.
Boiling is a rapid phenomenon.
Evaporation takes place at ................. .
Match the column
| Column A | Column B |
| (a) Blowing air increases | (1) Increase in intermolecular separation |
| (b) Increase in pressure increases | (2) Pendulum of a clock |
| (c) Thermal expansion |
(3) Cooking utensils |
| (d) Invar | (4) Boiling point |
| (e) Pyrex glass | (5) Evaporation |
During boiling or vaporization
Do all the molecules of a liquid take part in evaporation? If not, explain your answer.
Why is cooling produced when a liquid evaporates?
Give reason for the increase in rate of evaporation of a liquid when air is blown above the liquid.
