Answer to Question #4856 in Physical Chemistry for Tim

Question

I have a little question.
A mixture of CO2 and N2 gases has an experiment density of 21922 mol/m3 at T=225K and Pressure= 68.759 MPa and Z=1.67661. What is density of this mixture of gases in mol/m3 by Peng-Robinson equation of state? (Mole fraction of Co2= 10.56%)

Answer 1

Using Peng-Robinson equation of state can be given by:

Z = PV_m/RT
V_m - molar volume of gases mixture

Hence, density in mol/m³ can be given by:

ρ = 1/V_m = 1/(4.5614×10^-5) = 21923.094 mol/m³