Answer to Question #206007 in Physical Chemistry for Kareena Max

Question

A mixture of 50 g of hexane (0.59 mol C6H14) and 100 g of nitrobenzene (0.82 mol C6H5NO2) was prepared at 273 K.

i.    What are the compositions of the phases?

ii.   in what proportions do they occur?

iii.   To what temperature must the sample be heated in order to obtain a single-phase?

Answer 1

1. We denote hexane by H and nitrobenzene by N.  The point x_N = 0.41, T = 290, occurs in the two-phase region of the diagram.  The tie line indicates the phase boundaries at x_N = 0.35 and x_N = 0.83 (the compositions of the two liquid phases).  

The ratio of the amounts of each phase is equal to the ratio of the distances l_a and l_b. 

 There is about 7 times more nitrobenzene-rich phase than the hexane-rich phase.  Heating the sample to 292 K takes it into a single phase region. 

II)