The molar heat of mixing for a Cu$-$Al alloy is $-10000.$ Xcu $.$ Xal $($J$)$ a$-)$Which solution model $($ideal$,$ Henrian, regular$)$ does this alloy follow? Why? b$-)$Write the expressions for the integral molar Gibbs free energy of mixing and calculate its value for Xcu$=0\mathrm{.}4$ at $227$C$.$ c$-)$Derive the integral molar entropy of mixing and calculate its value for Xcu$=0\mathrm{.}4$ at $227$C d$-)$Derive the integral molar volume of mixing and calculate its value for Xcu$=0\mathrm{.}4227$C e$-)$ Calculate the activity of Cu in alloy of composition $,40$Cu$-60$Al at $227$C please do not answer in chatgpt or any ai's