Consider a mixture of molecules of type A and B to which a small amount of type C molecules is added. Assume that the Gibbs free energy of the resulting tertiary system is given by

= where n = n+ng+nc, nc nA, and nc

The quantities (P,T), =(P,T), and = (P,T) are the chemical potentials of pure A, B, and C, respectively, at pressure P and temperature T. For simplicity, assume that ==

c. To lowest order in the mole fraction xc, compute the shift in the critical temperature and critical mole fraction of A due to the presence of C.

Transcribed Image Text:

G(P,T, na, na, nc)=n +ng+ ncc + RTn In (xA) +RTng In (xg) +RTnc In (xc) + AnnB/n+Ananc/n + AinBnc/n,