3 [Computer-based calculation] Calculate the molar volume and compressibility factor of gaseous CO2 at 0.001, 0.1, 1.0, 10.0, 70.0 and 75.0 bar using the Virial, RK and SRK e

Temperature of the gas is 35◦C. For your calculations, consider: Tc = 304.2 K, Pc = 73.83 bar, ω = 0.224 and molar mass of 44.01 g mol−1

Need help, this is what ive done

%%% Module 1
% Problem 1 Task 3
%    Gaseous CO₂ at 35degC and 0.001, 0.1, 1.0, 70 and 75bar. Calculate V and Z for (a)
%    Virial EOS, (b) RK EOS, (c) SRK EOS and (d) PR EOS

% Critical properties
Pc = 73.83; % in bar
Tc = 304.2;% in K
w = 0.224; % accentric factor

% System properties
T = 35. + 273.15; % in K
P = 75.; % in bar
R = 8.3145e-5; % in m3.bar/(K.mol)

%%
%% (a) Virial EOS
%%
B = -194.; % in cm^3/mol
C = 15300; % in cm^6/mol^2

% Calculating Vguess (assuming ideal gas)
R2 = R * 100.^3; % in cm3.bar/(mol.K)
Vguess = T * R2/ P % in cm3/mol

Vguess = 341.6151

% Calculating the volume using the FZERO function
V_virial = fzero(@(V) P*V/(R2 * T) - (1.+B/V +C/(V^2)), Vguess) % in cm3/mol

V_virial = 136.5746

% Calculating Z
Z = P * V_virial/(R2 * T) 

Z = 0.3998

[Davide Masiello]

At first glance, your code seems fine. What is the problem?

[Candi Chevapravatdumrong]

I thought I had made a mistake with one of the values for B and C in the equation