Express the Internal Energy and Entropy as a Function of T and V for a homogeneous fluid. Develop the same relations using the isothermal compressibility and the volume expansivity coefficients.

Respuesta :

Answer:

[tex]dU=C_{v} dT+(T(\frac{\beta }{\kappa }) -P)dV[/tex]

[tex]dS=C_{v} \frac{dT}{T} +(\frac{\beta }{\kappa } ) dV[/tex]

Explanation:

The internal energy is equal to:

[tex]dU=C_{v} dT+(T(\frac{\delta P}{\delta T} )_{v} -P)dV[/tex]

The entropy is equal to:

[tex]dS=C_{v} \frac{dT}{T} +(\frac{\delta P}{\delta T} )_{v} dV[/tex]

If we write the pressure derivative in terms of isothermal compresibility and volume expansivity, we have

[tex]\frac{\delta P}{\delta T}=\frac{\beta }{\kappa }[/tex]

Replacing:

[tex]dU=C_{v} dT+(T(\frac{\beta }{\kappa }) -P)dV[/tex]

[tex]dS=C_{v} \frac{dT}{T} +(\frac{\beta }{\kappa } ) dV[/tex]