Important Notice: In this exam, some data are directly generated from your student ID$.$ The $x,Y,Z$

codes are the last three digits of your ID$,$ respectively. For example, if this is your student ID:

$060100351,$ the $x=3,Y=5,Z=1.$

The Cr$-$Ni binary system at $1xYZ$ K exhibits a regular solution. For $x_{Ni}=0\mathrm{.}24$ composition,

activity value was obtained as $a_N=036.$ Using the given information answer the questions:

a$)$ For $x_{Ni}=0\mathrm{.}4x$ composition calculate the activity and activity coefficient values of both $Cr$ and

$Ni.$

b$)$ Calculate the mixing free energy, mixing enthalpy and mixing entropy values of the solution

$(x_{Ni}=0\mathrm{.}4x).$

c$)$ Empiric equation to calculate equilibrium vapor pressure of pure Chromium is given below.

Calculate the equilibrium partial pressure of Chromium in the $Cr-Ni$ alloy $).$

$In{P}_{(Cr)}^o=-\frac{45590}{T}-1,27lnT+23,93(atm)$

d$)$ If temperature was decreased from $1xYZK$ to $1000K,$ would you expect higher, lower or the

same activity coefficient value for $Cr$ and $Ni?$ Explain.

e$)$ Describe the ${}_{?}-$function $($interatomic bond parameter$).$ Calculate$/$find the $-$ function for

the solution. Explain$/$compare the bond strengths for the solution. Is it an endothermic or

exothermic reaction? Does it require energy?