Evaporation is surface phenomenon.Greater is surface area greater is evaporation and vice versa.For example, sometimes a saucer is used if tea is to be cooled, quickly.This is because evaporation from the larger surface area of saucer is more than that of the smaller surface area of the tea cup.
At high temperature, rate of evaporation is high because at high temperature kinetic energy of molecules increases so high that they overcome the intermolecular forces ,and, evaporate rapidly.For example, water level in a container with hot water decreases earlier than that of a container with cold water.This is because hot water evaporates earlier than hot water. Itermolecular Forces:
If intermolecular forces are stronger, molecules face difficulty in evaporation. For example, water has strong intermolecular forces than alcohol,therefore alcohol evaporates faster than water.
Vapour pressure depends upon the nature of liquid.Polar liquids have low vapour pressure than that of non-polae liquids at the same temperature.This is because of the, strong intermolecular forces between the polar molecules of liquids.For example , water has less vapour pressure than that of alcohol at same temperature. Size of Molecules:
Small size molecules can easily evaporate than big size molecules hence , small size molecules exert more pressure.For example,hexane (C H ) is a small sized molecule as compared to decane (C H ).C H evaporates and exerts more pressure thanC H . Temperature:
At high temperature, vapour pressure is higher than at low temperature. At the elevated...
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