Question

Define Latent heat of vaporization and Latent heat of fusion

Answer 1

 The energy required in calories to completely convert one gram of water to steam without increasing the temperature is called the latent heat of vaporization. It is called latent heat because it does not increase the temperature. 

Latent heat of fusion of ice is heat energy required in calories by one gram of ice to completely convert itself into water without increase in temperature

Answer 2

Latent heat of vaporization:

The "amount of heat" needed to convert "unit mass of liquid" into its "vapour state" without change in its temperature is known as "latent heat of vaporization".

Example: The "latent heat of vaporization" of water is "540 cal/g/°C".

Latent heat of fusion:

The latent heat of fusion can be described as a "change in the amount of heat" when a solid converts into a liquid at "atmospheric pressure" at its "melting point".

Example: The latent heat of fusion of "water" is "79.72 cal/gram".