PPT Slide
- When one mole of substance melts, the enthalpy change is the heat of fusion (_H fus ):
- When one mole of a substance vaporizes, the enthalpy change is the heat of vaporization (_H vap ):
- Any change in a systemís total energy occurs through changes in the kinetic and potential energy components:
- A moleculeís E k contributions come from its motion through space, the rotation and the vibration of the molecule.
- E p contributions are forces in atoms between nuclei and electrons, between the nucleons and between atoms in each chemical bond.