Latent Heat

"The amount of heat required to change its state of any substance without 

changing its temperature is called latent heat."
 

 

As we know,

➡Quantity of heat is directly proportional to mass of substance.

Q ∝ m

Q = m L 

L = Q/m 

➡The SI unit of latent heat is joules per kg

Types of latent Heat:

➡Latent heat is of two types

1. Latent heat of fusion

2. Latent heat of vaporization

➡1. Latent heat of fusion:

"The amount of heat required to convert unit mass of a substance from solid to 

liquid without change in temperature is called latent heat of fusion."

➡Latent heat of fusion of ice is 80 calories per gram.

➡2. Latent heat of vaporization:

"The amount of heat required to convert unit mass of substance from liquid to 

Vapour without changing its temperature is called latent heat of vaporization."

➡Latent heat of vaporization of water is 540 calories per gram.