EVAPORATION AND CONDENSATION

Evaporation and condensation in a closed vessel

The factors effecting evaporation are:
1. Surface area of the container
2. Temperature of the surrounding
3. Humidity
4. Pressure
Etc…….




Evaporation: this process is explained as follows:

• When the molecules on the surface are collided against each other, there will be transfer of energy between them. When one of the molecules gets sufficient energy it gets transferred into the phase that has predominantly higher entropy.

• The rate of evaporation is defined as the number of molecules that are getting them converted into other phase per unit time. From this it can be understood that rate of evaporation depend on the temperature[which is the only cause for kinetic energy of the molecules] and the area[factor deciding the number of molecules :there by deciding number of collisions]

• Humidity only affects the equilibrium point that has to reach for the system to have minimum energy and maximum entropy.


The rate of evaporation to be constant in a closed vessel can also be explained by the fact that rate of reaction is directly proportional to number of fruitful collisions which is always constant.

Thus the graph between condensation & evaporation in closed vessel is:
the rate of condensation increases as the number of molecules