When the liquid is heated at its boiling point vaporization by keeping the pressure constant, the substances present in the liquid attain satisfactory amount of energy to defeat the inter molecular forces that bounds together with the substance of the liquid. Thus they will get away from the liquid as separate molecules of vapor till the completion of the vaporization. Thus, the boiling point vaporization is termed as boiling point. The boiling point temperature is left as a constant accordingly all the liquid gets converted into a gas.
Accordingly for each and every substance an assured amount of heat is applied in order to release a sufficient amount of molecules. This kind of heat production is called as latent heat of vaporization of the material. The maximum capacity of the heat applied to that substance will usually undergo significant changes depending upon the condition.
For example, the amount of heat needed to transform one gram of water to vapor at its boiling point at one atmospheric pressure, i.e., the heat of vaporization of water, is roughly around 540 calories. Further substance requires other amount.
Vaporization definition: it is defined as the liquid substance gets transformed into either gas or vapor. But certainly there are no specific differences between gas and a vapor. Because the term gas is used normally to explain a matter that appear in the gaseous state under normal situation of temperature and pressure. Thus the vapor is defined as the gaseous state of a material that exists regularly as a liquid or gas.
The increase in vapor pressure of the liquid at certain particular temperature determines the increase in boiling point of the liquid.
Thus the pictorial representation of the boiling point vaporization has been shown. In that the vapor pressure versus temperature of the liquid is drawn. It indicates that the liquid having maximum vapor pressure have the lowest common boiling points.
For example, at any specified temperature, propane has the maximum vapor pressure of any of the liquids in the graph. It also has the lowest usual boiling point (-42.1 °C), where the vapor pressure arc of propane (the purple line) intersect the flat pressure line of one impression atm of total vapor pressure.