Question

Consider a solution of two similar liquids which are miscible in all proportions over a wide range of temperatures. The excess Gibbs energy of this solution in adequeately represented by the equation

gE=Ax1x2

where A is a constant depending only on temperature. Over a wide range of temperature the ration of the vapor pressure of the pure components is constant and equal to 1.649. Over this same range of temperature the vapor phase may be considered ideal.
At azeotrope, what is the value of lnγ1γ2?

Answer 1

Answer:

The two similar liquids which are missible in all property over a wide range of temperature.

gE=A$x_{1} x_{2}$

here A=constant

over a wide range of temperature the ratio of the vapour pressure of the pure components is constant that is 1.649

$\frac{P^{5}_{2}  }{P^{5}_{1}  } =1.649$

$\frac{P_{2}^{5}  }{P_{1} ^{5} } =exp[\frac{A}{RT} (x^{2}_{2}  -x^{2} _{1} )]=1.649$

$\frac{A}{RT} (x^{2} _{2} -x^{2} _{1} )=ln1.641=1/2$\

$x_{1} =0.25$