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Why does the kinetic theory of gases neglect potential energy ?

  1. May 5, 2013 #1
    My textbook says that the forces of intermolecular attraction between gas molecules are very weak due to large intermolecular spaces between them , that's why they're negligible , Does this have a relation with "force is inversely proportional to the square of distance " (again , I don't know if this rule even applies here !) and my textbook also says that due to that , the potential energy is = Zero , what does that have to do with weak intermolecular forces that are negligible ?
    Last edited: May 5, 2013
  2. jcsd
  3. May 5, 2013 #2


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    Staff: Mentor

    Forces between atoms in a gas usually do not follow an inverse square law - they drop even quicker with increasing distance.

    If forces are negligible, the potential "at infinity" and the potential at real distances is nearly the same, therefore the potential energy (defined as this difference) is negligible.
  4. May 5, 2013 #3
    Thank you ! This was really helpful :smile:
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