At 20°C and 0.073 bar, a binary liquid mixture of cyclohexane (1) and toluene (2) is in vapor–
liquid equilibrium. The liquid mole fraction of cyclohexane is measured to be x1 = 0.471. Assume that the liquid phase nonideality can be represented by the two-suffi x Margules equation. Answer the following questions.

(a) From this measurement, determine the value of the two-suffi x Margules parameter, A.

(b) Are the like interactions or the unlike interactions stronger? Explain.

(c) Based on this model fi nd the Henry’s law constants for cyclohexane in toluene and toluene in cyclohexane.

(d) What is the composition of the vapor phase?

(e) If 7 moles of cyclohexane and 3 moles of toluene are mixed together at 20°C and 0.073 bar, how many total moles of liquid form?