Question

Define latent heat of evaporation and latent heat of fusion.

Answer 1

Hint: Latent heat can be considered as the energy or heat that is absorbed or released during a phase change of a substance. Phase change can either be from a gas to solid or liquid to solid and vice versa.

Complete step-by-step solution:
Latent heat is the work needed to overcome the attractive forces that hold atoms and molecules together in a substance. In general, energy required by a substance to either freeze, boil or melt is referred to be latent heat. Latent is the word that originated from the Latin word ‘latere’, which means to hide or cover up. There are different types of latent heat that can occur.
The latent heat of evaporation is the heat released or absorbed when matter disintegrates, phase changes from liquid to gas or changing stage from fluid to gas stage at a consistent temperature.it is also called latent heat of evaporation.
Water has the most elevated latent heat of evaporation. As a result of high heat of evaporation, the vanishing of water has a cooling impact and a warming impact is caused by its build up. It is characterized as the measure of heat to transform one gram of a fluid into a gas without an ascent in the temperature of the liquid.
Latent heat of fusion is the heat released or absorbed when matter melts changing its phase from solid to liquid or from strong to fluid structure at a consistent temperature. It can also be defined as enthalpy change of any measure of substance when it dissolves. The point where the latent heat of fusion becomes a unit of mass, it is typically called the specific heat of fusion, while the molar heat of fusion is the enthalpy change per measure of substance in terms of moles.
The fluid stage has a higher vitality than the solid one. A point when fluid water is cooled down, temperature falls just underneath the line of the point of solidification i.e., at zero-degree temperature. This temperature stays consistent at the point of solidification, simultaneously the water takes desirable shape. The enthalpy of fusion is a positive value.

Note: Helium is the only exception with negative enthalpy of fusion at temperatures below 0.3K. An important point should be noted regarding latent heat that the temperature of the substance remains constant.