Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Chemical potential

  1. Nov 27, 2013 #1
    in class, we just learned that the chemical potential was μ=∂G/∂N

    i'm looking in my book and it says that μ=-T(∂S/∂N) this looks alot like the partial of heat energy with respect to N. is my interpretation correct?

    (assuming my interpretation was correct): so qualitatively, the chemical potential is the heat energy carried by a constituent particle of a system?
     
  2. jcsd
  3. Nov 28, 2013 #2

    DrDu

    User Avatar
    Science Advisor

    When taking the partial derivative, S is a function of what besides N?
    Clearly you can write
    ##dS(V,U,N)=1/T dU+p/T dV + \mu/T dN ##, so ##\mu=T (\partial S/\partial N)_{V, U}##
     
  4. Nov 28, 2013 #3
    okay silly question: where does the minus come from? Q=-TdS, but that minus gets cancelled when rearranging to solve for dS like you did so then you end up with positive like you did.
     
  5. Nov 28, 2013 #4

    DrDu

    User Avatar
    Science Advisor

    There may be different sign convention. The most common one which I also use is Q=TdS.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook