latent heat
Nishant Kondia
Objectives
❏ Define specific latent heat
❏ Formula of specific latent heat
❏ Determine the two types of specific latent
heat
Latent heat
The heat absorbed or the heat released at constant
temperature during a change of phase is known as
latent heat.
The four main changes of phase :
● Melting
● Boiling
● Condensation
● solidification
Three common characteristics in the process of
change of phase
● Particular temperature
● Heat energy transferred
● Constant temperature during change of phase
❏ The amount of heat required to change the phase of
substance depends on the mass and the type of
material.
Specific latent heat
The specific latent heat of a substance is the amount of heat required to
change the phase of 1 kg of the substance at a constant temperature.
The formula for specific latent heat is
The SI unit of specific heat is
J KG-1
Example
1. Specific latent heat of fusion
Latent heat of fusion is the heat absorbed by a melting solid
2. Specific latent heat of vaporization
Latent heat of vaporization is the heat absorbed during
boiling.