Thermodynamic Relations

Perfect Liquids/Solids:

Heat Capacities:

Internal Energy:

Entropy:

From Internal Energy...

du=Tds−Pdv⟶ds=duT+PTdv⟶ds=CdTT⟶Δs=s2−s1=Cln⁡(T2T1)

Ideal Gas:

Fully compressible:

Internal Energy/Enthalpy:

Heat Capacities:

Internal Energy:

du=CvdT+∂u∂v|Tdv=CvdT

Enthalpy:

dh=CpdT+∂h∂P|TdP=CpdT

Entropy:

From Internal Energy in terms of Specific Volume...

ds=duT+PTdv⟶ds=CvdTT+RWdvv⟶Δs=Cvln⁡(T2T1)+RWln⁡(v2v1)

From Enthalpy in terms of Pressure...

ds=dhT−vTdP⟶ds=CpdTT−RWdPP⟶Δs=Cpln⁡(T2T1)−RWln⁡(P2P1)

Internal Energy:

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