Specific latent heat

Latent heat is the energy involved when matter changes states. There are two types of latent heat:

Specific latent heat of fusion

This energy is supplied to break the forces between atoms and molecules during melting from solid to liquid. The average distance between the particles is slightly further in liquid than in solid.

Specific latent heat of fusion is the quantity of heat energy required to convert unit mass of solid to liquid without any change in temperature

This energy is released when a liquid changes to solid.

Specific latent heat of vaporisation

This energy is supplied to break completely the forces between atoms and molecules during boiling or vaporisation. As a result, the average distance between the particles in gas is much further than in liquid.

In addition to that, the gas has to expand against the atmospheric pressure. This requires additional energy. As such, the specific latent heat of vaporisation is much larger than the specific latent heat of fusion.

Specific latent heat of vaporisation is the quantity of heat energy required to convert unit mass of liquid to gas without any change in temperature.

Beside boiling, this energy is also required during evaporation of liquid water.

During evaporation, the higher speed particles at the surface of the liquid escape from the liquid to the air. As a result, the average speed of the particles left is smaller, causing a lowering of temperature in the liquid. Thus, evaporation causes cooling

This energy is released when a gas condenses into liquid.

print