Understanding Expansion, Compression and Entropy Coefficients

AI Thread Summary
The discussion focuses on deriving the temperature change with respect to volume at constant entropy, expressed as (DT/DV)s. The user starts with known thermodynamic relationships involving expansion and compression coefficients, and attempts to manipulate these to find the desired derivative. They propose that (DT/DV)s can be expressed as a*T/Cv*k, indicating a relationship between various thermodynamic properties. The conversation includes mathematical formulations and seeks confirmation on the correctness of the derived expression. Overall, the thread emphasizes the connection between thermodynamic coefficients and their implications for understanding entropy and temperature changes.
tsuwal
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So, until now I know:
(DV/DS)p=(DT/Dp)s=a*T/cp*(rho) (enthalpy)
(Dp/DT)v=(DS/DV)t=-a/k (helmoltz)
(DS/Dp)t=-(DV/DT)p=-Va (gibbs)

a=expansion coefficient
k=isothermal compression coefficent
cp=heat capacity at constante pressure

I want to deduce DT/DV at constant entropy=(DT/DV)s. BUT HOW?
Let me try to write S(T,V), then,
dS=Cv/T*dT-a/k*dV
putting S=0, i get,
a/k*dV=Cv/T*dT <=> (DT/DV)s=a*T/Cv*k

am I right?
 
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Is this the one you want?

\begin{array}{l}<br /> T = {\left( {\frac{{\partial U}}{{\partial S}}} \right)_V} \\ <br /> {\left( {\frac{{\partial T}}{{\partial V}}} \right)_S} = \left[ {\frac{\partial }{{\partial V}}{{\left( {\frac{{\partial U}}{{\partial S}}} \right)}_V}} \right] = \frac{{{\partial ^2}U}}{{\partial V\partial S}} \\ <br /> \end{array}

and

\begin{array}{l}<br /> P = - {\left( {\frac{{\partial U}}{{\partial V}}} \right)_S} \\ <br /> {\left( {\frac{{\partial P}}{{\partial S}}} \right)_V} = - \left[ {\frac{\partial }{{\partial S}}{{\left( {\frac{{\partial U}}{{\partial S}}} \right)}_V}} \right] = - \frac{{{\partial ^2}U}}{{\partial S\partial V}} \\ <br /> \end{array}

Therefore

{\left( {\frac{{\partial T}}{{\partial V}}} \right)_S} = - {\left( {\frac{{\partial P}}{{\partial S}}} \right)_V}
 


Hey, thanks for worring so much, but until there I knew...
I want to evaluate that derivative further and write in terms of a,k,Cv,Cp,T,p,... as I did
(∂T/∂p)s=a*T/cp*(rho)
 
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