Problem 8.14: At 100 °C, water (w) and nitrobenzene (n) are only partially miscible. At this temperature, the solubility of nitrobenzene in water is 0.147 mol %, while the solubility of water in nitrobenzene is 8.3 mol %.
a) Assuming that each liquid phase behaves ideally with respect to the concentrated species (that is, w 1, in the water-rich phase and n 1 in the nitrobenzene-rich phase), calculate the activity coefficient of each component at infinite dilution.
b) Show that if boiling occurs under constant pressure, the boiling temperature must remain constant until one of the two liquid phases completely evaporates.
c) One hundred mol of the water-rich phase are mixed with 100 mol of the nitrobenzene-rich phase at 100
°C and the pressure is adjusted until boiling starts. What is the pressure?
d) Calculate the composition of the vapor phase in the previous part.
e) If boiling continues indefinitely, which liquid phase will disappear first?
f) Draw a qualitative Pxy graph for this system at 100 °C. Show all the important features on the graph. The saturation pressure of nitrobenzene at 100 °C is 21 mmHg.