Heat of vaporization

The heat of vaporization is the temperature at which an element is transformed from fluid into gas at a certain pressure. This process is calculated at boiling point of an element. The units of measurements are in J/mol or Kj/mol (molar enthalpy of vaporization). However, units like kj/kg or J/g are used as well as older divisions like cal/g and kcal/mol are also functional.

Heat of Vaporization graph

The heat of vaporization is the temperature at which an element is transformed from fluid into gas at a certain pressure.

A simple physical model of heat of vaporization of liquid to gas has been projected lately. It is proposed that the heat needed to release a particle from the fluid is correspondent with the energy required to surmount the exterior resistance of the fluid. In addition to this, the model gives way for calculation of latent temperature through multiplication of the surface tension, and quantity of particles in the fluid by the surface area covering a particle.

The premeditated latent heat of vaporization standards for the 45 examined constituents concurs perfectly with the tests carried. The heat of vaporization can be observed as the energy needed to beat the intermolecular contact of the fluid. According to the International Union of Pure and Applied Chemistry (IUPAC), Helium has a low heat of vaporization as the forces between its particles are weak while the heat of vaporization of water is high due to the strong hydrogen bonds within it, therefore, more energy required to vaporize it.

When the strength of intermolecular contact is measured, caution should be taken regarding their heat of vaporization measurements because these intermolecular forces might persist to a certain level in the gas stage, hence, giving a low measurement when calculations are done. It is possible to measure this heat at boiling point, where the temperature at which the pressure of the vapor of the liquid equals the pressure surrounding the fluid.

According to the International Union of Pure and Applied Chemistry (IUPAC), standard boiling point is the temperature at which boiling takes place below a pressure of one bar. Saturation temperature means the boiling point of a substance. This is the temperature of an equivalent saturation temperature at which the fluid turns to mist. Saturation takes place through thermal energy.

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