Chapter 12, Problem 12.33P

Problems 12.29 through 12.33 refer to the xy diagram provided in Fig. 12.23. This diagram shows xy curves both for ethanol(1)/ethyl acetate(2) and for chloroform(1)/tetrahydrofuran(2), both at a constant pressure of 1 bar. The curves are intentionally unlabeled. Readers should refer to Figs. 12.19 through 12.22 to deduce which curve is for which pair of substances.

Figure 12.23: xy dia¬gram for ethanol(1)/ethy1 acetate( 2) and for chloro-form(1)/lctrahydrofuran(2), both at a constant pressure of 1 bar. Note that the curves arc intentionally unlabeled, but they can be identified based on infor-mation presented in Figs. 12.19 through 12.22.

12.33. Consider a binary liquid mixture for which the excess Gibbs energy is given by $G^E/RT=A{x}_1{x}_2$ . What is the minimum value of A for which liquid/liquid equilibrium is possible?