Question

Choose the correct statements from the following

• A. Evaporation takes place from the surface of a liquid at all temperatures.
• B. The rate of evaporation depends upon the area of the exposed surface of the liquid, nature of the liquid and its temperature.
• C. The cooling produced in evaporation is a consequence of the fact that a liquid has latent heat.
• D. The rate of evaporation depends on the pressure to which the liquid is subjected.

Answer 1

Answer: (A), (B), (C), (D)

Evaporation is a type of vaporization of a liquid that occurs from the surface of a liquid into a gaseous phase. So there is loss of energy due to latent heat of the liquid.

For molecules of a liquid to evaporate, they must be located near the surface, they have to be moving in the proper direction, and have sufficient kinetic energy to overcome liquid-phase inter-molecular forces. When only a small proportion of the molecules meet these criteria, the rate of evaporation is low. Since the kinetic energy of a molecule is proportional to its temperature, evaporation proceeds more quickly at higher temperatures and high surface area.

Evaporation happens faster if there is less exertion on the surface keeping the molecules from launching themselves.

So all the options are correct.