For the system ethanol$(1)/$toluene$(2)$ the following VLE data were measured at $45C.$

Table $2\mathrm{.}4$ VLE data for the system ethanol$(1)/$toluene$(2)$ at $45C.$

For the liquid mixture of composition $x_1=0\mathrm{.}30$ :

a$.$ Calculate the activity coefficients for both components.

b$.$ Calculate $G^E$ and $G.$

c$.$ Knowing that $\frac{H^E}{R}T=0\mathrm{.}437,$ estimate $G^E$ at $60C?$