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Entropy principle

  1. Nov 14, 2014 #1
    Whilst I understand that entropy is a measure of the number of specific ways in which a system may be arranged. The units for entropy don't make sense to me intuitively. Why joules per kelvin? What way at all does that show how "disordered" a system is. When I hear joules per kelvin, I think of energy/average thermal energy.

    What does the energy and temperature represent in this case?
     
  2. jcsd
  3. Nov 14, 2014 #2

    mfb

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    2016 Award

    Staff: Mentor

    You can transform it to a dimensionless value with the Boltzmann constant. And that is just a unit conversion factor.
     
  4. Nov 15, 2014 #3

    A.T.

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    Here is a nice video on why the "disorder" interpretation of entropy is misleading:



    More links in the video description on youtube.
     
  5. Nov 15, 2014 #4

    td21

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    Why joules per kelvin?
    It follows from the second law of thermodynamics.
    What does the energy and temperature represent in this case?
    It is the change of entropy. In this case, energy is the heat transferred into the system and temperature is the absolute temperature (in Kelvin) the system at.
     
  6. Nov 19, 2014 #5
    So the temperature is the absolute temperature before the heat energy is transferred into the system?
     
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