POLYMATH Report          NLE 
 Explicit Equations 2016-May-31 

Calculated values of explicit variables
    Variable Value
1 V 0.065
2 Pc 72.9
3 R 0.08206
4 T 300
5 omega 0.225
6 Tc 304.2
7 a 3.65392
8 b 0.029668
9 m 0.826312
10 alpha 1.01148
11 P 96.129
12 Tr 0.986193
13 Pr 1.31864
14 z 0.253814

Problem source text
# S. 15* - Complex consecutive calculations
# Gas pressure from SRK equation of state
# Verified Solution: P = 96.129, z = 0.253814
#Ref.: Prob. 2.9 in Problem Solving in Chemical…
P = R*T/(V-b)-alpha*a/(V*(V+b)) # Pressure (atm)
a = 0.42747*R^2*Tc^2/Pc #SRK constant
b = 0.08664*R*Tc/Pc #SRK constant
alpha = (1+m*(1-sqrt(T/Tc)))^2 #SRK constant alpha
m = 0.48508+1.55171*omega-0.1561*omega^2 #SRK constant m
Tc = 304.2 #Critical temperature (K)
Pc = 72.9 #Critical pressure (atm)
R = 0.08206 #Gas constant (L-atm/gmol-K)
omega = 0.225 #Acentric factor
T = 300 #Temperature (K)
V=0.065 # Volume (L/g-mol)
#P = 100 #Pressure (atm)
Tr=T/Tc
Pr=P/Pc
z=P*V/(R*T)

Matlab formatted problem
Create m file called PolyExplicit.m and paste the following text into it.
% S. 15* - Complex consecutive calculations
% Gas pressure from SRK equation of state
% Verified Solution: P = 96.129, z = 0.253814
% Ref.: Prob. 2.9 in Problem Solving in Chemical…
%Volume (L/g-mol)
V = 0.065;
%Critical pressure (atm)
Pc = 72.9;
%Gas constant (L-atm/gmol-K)
R = 0.08206;
%Temperature (K)
T = 300;
%Acentric factor
omega = 0.225;
%Critical temperature (K)
Tc = 304.2;
%SRK constant
a = 0.42747 * R ^ 2 * Tc ^ 2 / Pc;
%SRK constant
b = 0.08664 * R * Tc / Pc;
%SRK constant m
m = 0.48508 + 1.55171 * omega - (0.1561 * omega ^ 2);
%SRK constant alpha
alpha = (1 + m * (1 - sqrt(T / Tc))) ^ 2;
%Pressure (atm)
P = R * T / (V - b) - (alpha * a / (V * (V + b)));
Tr = T / Tc;
Pr = P / Pc;
z = P * V / (R * T);

General Settings
number of explicit equations: 14
reporting digits 8