تسجيل الدخول

تسجيل

Heat of Vaporization

المؤلف:  GEORGE A. HOADLEY

المصدر:  ESSENTIALS OF PHYSICS

الجزء والصفحة:  p-284

2025-11-25

729

When heat is applied to a beaker of water, its temperature will rise until the boiling point is reached. After this no further increase in the temperature will take place, however rapid the boiling. By continuing the experiment, the water can all be changed into vapor. The number of heat units required to vaporize a unit mass of liquid without changing its temperature is its heat of vaporization. When the vapor changes to a liquid, the same amount of heat will be given out. Experiment has shown that the heat of vaporization of water is 537 calories. This means that the heat required to boil away 1 g. of water is 5.37 times as much as is required to raise its temperature from zero to 100°.