Question

(i) what is meant by latent heat of vaporisation and (ii) latent heat of fusion. State its effect of (i) surface area (ii) nature of the liquid on the rate of evaporation

Answer 1

Latent heat of vaporization is the amount of heat absorbed by a liquid when changing its state from liquid to gas, at this point there is no change in temperature and hence the name 'latent'

Similarly, latent heat of fusion is the amount of heat absorbed by a solid when changing from solid to liquid.

• larger the surface area faster the evaporation.
• More volatile liquid faster the evaporation