Question

what is meant by the word latent heat of vapourization

Answer 1

the quantity of heat that changes unit mass of a liquid completely into gas as its boiling point without any change in its temperature is called its latent heat of vapourization.

Answer 2

Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process that is specified in some way. An example is latent heat of fusion for a phase change, melting, at a specified temperature and pressure.The term was introduced around 1762 by Scottish chemist Joseph Black. It is derived from the Latin latere (to lie hidden). Black used the term in the context of calorimetry where a heat transfer caused a volume change while the thermodynamic system's temperature was constant.