Question

Define the following and state their numerical value in SI system:
(a) Specific latent heat of fusion of ice
(b) Specific latent heat of vaporisation of steam

Answer 1

a) Specific latent heat of fusion of ice:

1. The specific latent heat of fusion is defined as the amount of heat energy required to change the state of a solid into liquid state at a constant temperature that is the melting point of the solid.
2. The specific latent heat of fusion of ice at $0^{0}C$ is defined as the ​amount of heat required to change one kilogram($1kg$) of ice into its liquid state that is water at $0^{0}C$ that is without any change in temperature.
3. The latent heat of fusion of ice in the SI system is,

$L_{ice}=3.36\times {10}^{5}JK{g}^{-1}$

b) Specific latent heat of vaporisation of the system:

1. The specific latent heat of vaporisation is defined as the amount of heat energy absorbed or released by a substance to change its state of liquid into the gaseous state​ at a constant temperature that is at the boiling point of the liquid.
2. The specific heat of vaporisation of water is defined as the amount of heat required to change the state of one kilogram($1kg$) of water at ${100}^{0}C$ to its gaseous state at the same temperature that is ${100}^{0}C$.
3. The value of latent heat of vaporisation of water in the SI system will be:

$L_{steam}=2260kJK{g}^{-1}$