Evaporation |
Boiling |
1. It is slow process |
1. It is a fast process |
2. Evaporation occurs spontaneously at all temperatures. |
2. Boiling occurs at the boiling point at which the vapour pressure of the liquid is equal to the atmospheric pressure. |
3. Evaporation takes place only at the surface of the liquid |
3. Boiling involves the formation of bubbles of vapour below the surface of the liquid. |
4. The rate of evaporation increases by increasing the surface area |
4. Surface area has no effect on the rate of boiling. |
Explain briefly the boiling point of a liquid. What is the effect of change in external pressure on the boiling point?
Separate portions of chloroform and water at the same temperature are poured on your hands. The chloroform feels colder. Account for this in terms of attractive forces.