//clc()
P1 = 40;//% ( nitrogen )
P2 = 60;//% ( ethane )
T = 325;//K
V = 4.5 * 10^-4;//m^3/mol
a1 = 0.1365;//N*m^4/mol^2
b1 = 3.86 * 10 ^ -5;//m^3/mol
a2 = 0.557;//N*m^4/mol^2
b2 = 6.51 * 10 ^ -5;//m^3/mol
Pc1 = 3394;//kPa
Tc1 = 126.1;//K
Pc2 = 4880;//kPa
Tc2 = 305.4;//K
R = 8.314;
Pideal = R * T / (V * 1000);//kPa
disp("kPa",Pideal,"(a)Pressure of Gas by the ideal gas equation = ")
y1 = P1/100;
y2 = P2/100;
a = (y1 * (a1^(1/2)) + y2 * (a2^(1/2)))^2;
b = y1 * b1 + y2 * b2;
Pv = ((R * T / (V - b)) - a / (V^2))/1000;
disp("kPa",Pv,"(b)Pressure of Gas by Van der waals equation = ")
Tc = y1*Tc1 + y2*Tc2;
Pc = y1*Pc1 + y2*Pc2;
Vc = R * Tc / Pc;//Pseudo critical ideal volume
Vr = V / Vc;//Pseudo reduced ideal volume
Tr = T / Tc;//Pseudo reduced temperature
//From fig 5.3, we get Pr = 1.2
Pr = 1.2;
Pk = Pr * Pc;
disp("kPa",Pk,"(b)Pressure of Gas by the Kays method = ")