A system is made up from propane, nbutane, and nhexane.
A liquid phase and a vapor phase are present.
(a) How many degrees of freedom does this system have?
(b) In only one of the statements below are the intensive variables specified just adequate to determine completely the state of the system. Which statement is it? (x is a liquid mole fraction. Substance 1 is propane, 2 is nbutane, 3 is nhexane.)
(i) T = 30° C, P = 1 atm
(ii) T = 30° C, x1 = 0.45, x2 = 0.20
(iii) x1 = 0.45, x2 = 0.20, x3 = 0.35
(iv) T = 30° C, P = 1 atm, x1 = 0.45, x2 = 0.20
(c) Using conditions as given in either (i), (ii), (iii) or (iv) of part (b) above, whichever is sufficient, find the temperature, pressure and all the liquid and vapor mol fractions in the system at equilibrium. Vapor pressure data are available in literatures (or assume it).