15. Discuss the various factors which affect the rate of evaporation. Latent heat evaporation of two liquids A and B is 100 J/kg and 150 J/kg respectively. Which
can produce more cooling effect and why? (5)

The correct answer is liquid B.

Explanation:

Latent heat of vaporization also known as the latent heat of evaporation. This latent heat transforms the particles of liquid into a gas without affecting its temperature. For example, the latent heat of evaporation for water is 40.8 kJ per mole, that is, 40.8 kJ per mole of heat is needed to transform water into vapor at 373 K.  

It is known that latent heat of evaporation of a liquid is directly proportional to the cooling effect it generates, that is, more the latent heat of evaporation more will be its cooling effect. Thus, it is clear that liquid B will show the more cooling effect as the latent heat of evaporation of liquid B is more in comparison to liquid A. Thus, more heat will be captivated by liquid B and will generate more cooling effect in comparison to liquid A.