The heat of vaporization formula is q = m x ?Hv, where "q" is heat energy, "m" is mass and "?Hv" is heat of vaporization. This represents the energy needed to heat a liquid into a gaseous state.Continue Reading
For example, the heat energy needed to turn 25 grams of water into steam (gaseous state) is: 25 grams x 2257 Joules/gram or 56425 Joules. The 2257 J/g is a predetermined value for heat of vaporization of water.
A practical application of the heat of vaporization is when a drop of methylated spirit put onto the hand evaporates. The hand feels cold because it provides the energy needed for the volatile liquid molecules to break free into gas.Learn more about Thermodynamics