Advertisements
Advertisements
प्रश्न
No heat is supplied to a liquid during evaporation. How does then the liquid change into its vapours?
Advertisements
उत्तर
Due to the weak intermolecular force of attraction, the molecules of a liquid move freely inside it. In the process, they collide with each other transferring energy between them. Molecules with higher kinetic energy reach the surface of the liquid. These molecules absorb some more heat from the surroundings to gain sufficient kinetic energy to overcome the force of attraction on them due to other molecules inside the liquid escaping from the surface into space. These escaping molecules form the vapour of the liquid. Thus, evaporation of the liquid happens even though no heat is supplied to it.
APPEARS IN
संबंधित प्रश्न
Evaporation is rapid on a wet day.
All molecules of a liquid take part in the process of evaporation.
Boiling is a rapid phenomenon.
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 |
The rate of evaporation of a liquid increases when:
The boiling point of a liquid is increased by
Do all the molecules of a liquid take part in evaporation? If not, explain your answer.
Give reason for the increase in the rate of evaporation of a liquid when temperature of liquid is increased.
What is the change in average kinetic energy of molecules of a liquid during boiling at its boiling point?
How is the heat energy supplied to a liquid used during boiling at a fixed temperature?
