Question$-2$

Consider vapor$-$liquid equilibrium of a binary mixture at $500K.$ The fugacity

coefficient in the vapor phase can be obtained, by an approach similar to calculating

partial molar properties in a mixture, as follows:

$ln(hat({)}_i)=[\frac{\text{d}\text{e}\text{l}(nln)}{del{n}_i}{]}_{P,T,n_j}$

where,

$ln()=(1+y_2)y_1{y}_2$

and $y_1,$ and $y_2$ are mole fractions of species$-1$ and species$-2$ in the vapor phase

respectively. The pure component properties of the two species at saturation

conditions are given below:

$($a$)$ Calculate the composition of the liquid phase in equilibrium with the

vapour phase of composition $y_1=0\mathrm{.}75$

$($b$)$ Calculate the total pressure of the system at VLE at the condition

described in part $($a$)$