Latent Heat


Temperature and Heat I - Concepts
Class - 7th ISO Subjects
 
 
Concept Explanation
 

Latent Heat

Latent Heat Of Vaporisation:

The latent heat of vaporisation of a substance is defined as the quantity of heat gained by 1 kg of the substance in changing from liquid to vapour state or from vapour to liquid state at constant temperature.

When you heat a liquid, its molecules start moving faster and gain kinetic energy. This shows as a rise in its temperature. At the boiling point, however, the heat supplied is used by the molecules to break away from the inter-molecular force and change into vapour molecules, rather than to move faster.This is why there is no change in the temperature. The heat required to help the molecules of liquid to overcome the inter-molecular forces and to escape as a vapour molecules is known as the latent heat of vaporisation.

Latent Heat Of Fusion:

The latent heat of fusion is defined as the quantity of heat gained by 1 kg of substance in changing from the solid to liquid at same temperature.

.... (More Text Available, Login?)
Sample Questions
(More Questions for each concept available in Login)
Question : 1

Which of the following are correct ?

(a) The latent heat of fusion is defined as the quantity of heat gained by 1 kg of substance in changing from the liquid to solid at same temperature.

(b) The latent heat supplied during the process is used by the molecules to overcome the intermolecular force, and not to raise the temperature.

Right Option : B
View Explanation
Explanation
Question : 2

The heat required to help the molecules of liquid to overcome the intermolecular forces and to escape as a vapour molecules is known as the _______________________ .

Right Option : C
View Explanation
Explanation
Question : 3

The latent heat of fusion is defined as the quantity of heat gained by 1 kg of substance in changing from the ________________________ at same temperature.

Right Option : A
View Explanation
Explanation
 
 
 


Students / Parents Reviews [10]