Explain the following terms. (i) Latent heat of fusion (ii) Latent heat of vaporisation

1. Latent heat of fusion:

• The quantity of heat required to convert unit mass of a substance from its solid state to the liquid state, at its melting point, without any change in its temperature is called its latent heat of fusion.
• The S.I. unit of latent heat of fusion is J/kg and its C.G.S. unit is cal/’g.

2. Latent heat of vaporisation:

• The quantity of heat required to convert unit mass of a substance from its liquid state to vapour state, at its boiling point, without any change in its temperature is called its latent heat of vaporisation.
• The S.I. unit of latent heat of vaporization is J/kg and its C.G.S unit is cal/g.