The Cu$-$Zn binary alloy at $1351$ K for the composition XZn $=0\mathrm{.}21$ is a dilute solution. If the partial

molar excess free energy of Zn is $5351$ J$/$mol$,$ answer the following questions.

a$)$ Calculate the activity, activity coefficient values of Zn$.$

b$)$ Calculate the mixing free energy of the solution.

c$)$ Calculate the activity, activity coefficient, partial molar free energy, partial molar enthalpy, partial

molar entropy values of Cu in the solution.

d$)$ For XZn $=0\mathrm{.}11$ composition, calculate the activity values of Cu and Zn$.$