1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Heat capacity (statistical physics)

  1. Feb 6, 2006 #1
    Hi. I've just started a course on statistical physics and the first assignment is this:

    A system possesses 3 energy levels, [tex]E_1 = \epsilon,[/tex] [tex]E_2 = 2\epsilon[/tex] and [tex]E_3 = 3\epsilon[/tex]. The degeneracy of the levels are g(E1) = g(E3) = 1, g(E2) = 2. Find the heat capacity of the system.

    I've forgotten all this thermodynamics stuff, so I would appreciate some hints :-)
     
  2. jcsd
  3. Feb 8, 2006 #2
    Anyone? Please :uhh:
     
  4. Feb 8, 2006 #3

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    If you are given a description of a system, what quantity do you first compute, from which you can determine other thermodynamic quantities ?
     
  5. Feb 20, 2006 #4
    Yes, yes, the partition function, I know :-)
     
  6. May 4, 2009 #5
    sum over states to get Q

    Q= exp{-B.E) + 2exp{-B.2E} + exp{-B.3E}

    B=kT Q=partition E=energy (two in front of second term beacuse of degenercy)


    U= - Diff (lnQ) w.r.t (B)

    U= internal energy prof can be found ( http://www.chem.arizona.edu/~salzmanr/480b/statt01/statt01.html)..... if you are interested

    gives U= E.exp(-B.E) + 4E.exp(-B.2E) + 3E.exp(-B.3E)

    makes sense highest energy has least probabilty of being populated but contributes three times as much to internal enrgy when it is. same would apply to the middle state but there is two of them so it is four instead of two.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Heat capacity (statistical physics)
Loading...