*S *as function of *P* and *T*. Integration of (92) again, for pure phase component yields:

(112)

Expansion in an ideal gas and a deviation term:

(113)

Solving the last integral in (113):

(114)

Extending the lower integration limit:

(115)

The first two terms of (110) are the *S *of a pure* hypothetical ideal gas*. If the system is a mixture ideal mixing entropy has to be added

(116)