Question

What is Latent heat of evaporation?

Answer 1

Hint- We must understand that the latent heat is the concept that relates to the heat required for phase change.

Complete step by step answer:
Let's start with the formal definition, latent heat is the heat/energy required for phase change from solid to liquid, liquid to gas or vice-versa.
Now, we all know that evaporation is a process in which the water changes from liquid to vapour state. So we can say that latent heat of evaporation is also known as latent heat of vaporization and it is a physical property of a substance. Basically, it is the heat/energy required to change the state of liquid to vapour at a constant temperature.

Another definition would be that, the latent heat of vaporization is also characterised as the amount of heat required to transform 1g of liquid to vapour at a constant temperature.

Also we must know that the latent heat of vaporization for water at 100℃ and atmospheric pressure is 2260KJ/Kg and for acetone is 518KJ/Kg at atmospheric pressure.

Additional Information:
We can understand that the addition or removal of latent heat never changes the temperature. Hence the temperature of the material remains the same.
Also the other types of latent heat are Latent heat of fusion which deals with the amount of energy required to change the state of solid to liquid at a constant temperature.
When we remove the latent heat from vapours they condense to a liquid without any change in temperature and hence latent heat is also known as hidden heat as it only changes the phase, not temperature.

Note: The student needs to understand what is latent heat and different processes related to it. It is also required to know the difference between latent heat and sensible heat. We can define that the latent heat is energy released or absorbed, by substance during a constant-temperature process and Sensible heat is heat exchanged by a substance in which the adding or removing of heat changes the temperature of the body or system.