P5C.4 1-Butanol and chlorobenzene form a minimum boiling azeotropic system. The mole fraction of 1-butanol in the liquid (x) and vapour (y) phases at 1.000 atm is given below for a variety of boiling temperatures (H. Artigas et al., J. Chem. Eng. Data 42, 132 (1997)). T/K 396.57 393.94 391.60 x 0.1065 0.1700 y 0.2859 0.3691 390.15 389.03 388.66 0.2646 0.3687 0.5017 0.6091 0.7171 0.6409 0.4505 0.5138 0.5840 0.7070 388.57 Pure chlorobenzene boils at 404.86 K. (a) Construct the chlorobenzene-rich portion of the phase diagram from the data. (b) Estimate the temperature at which a solution whose mole fraction of 1-butanol is 0.300 begins to boil. (c) State the compositions and relative proportions of the two phases present after a solution initially 0.300 1-butanol is heated to 393.94 K.