Enthalpy of vaporization: Difference between revisions

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Revision as of 23:57, 1 October 2006

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absorbed by the substance), whereas enthalpy changes of condensation are always negative (heat is released by the substance).

The enthalpy change of vaporisationvaporization can be viewed as the energy required to overcome the [[Chemical bond#Intermolecular interactions|intermolecular interactions]]

in the liquid (or solid, in the case of [[sublimation]]). Hence [[helium]] has a particularly low standard enthalpy change of

vaporisation, 0.0845 kJ/mol, as the [[van der Waals force]]s between helium [[atom]]s are particularly weak. One the other hand,