| |
| | Home > Riverhead, New York, NY, 11901, Riverhead Real Estate, Riverhead Yellow Pages, Riverhead Classifieds, ... (Site not responding. Last check: 2007-10-10) |
 | | The standard enthalpy change of condensation (or heat of condensation) is numerically exactly equal to the standard enthalpy change of vaporisation, but has the opposite sign: enthalpy changes of vaporisation are always positive (heat is absorbed by the substance), whereas enthalpy changes of condensation are always negative (heat is released by the substance). |
 | | The enthalpy change of vaporisation can be viewed as the energy required to overcome the intermolecular interactions in the liquid (or solid, in the case of sublimation). |
 | | An alternative description is to view the enthalpy change of condensation as the heat which must be released to the surroundings to compensate for the drop in entropy when a gas condenses to a liquid. |
| www.riverheadnyus.com /section/Standard_enthalpy_change_of_vaporization (645 words) |
|