Bicol University

CHE 130

1. Calculate the volume (in L) of an equimolar gaseous mixture methane (1), propane (2) and npentane (3) at 100°C, 1 atm. Use the virial EOS.
Given: equimolar gaseous mixture
T=100℃∨373.15 K
p=1atm
Required: volume
Solution:
Ideal gas equation
pV=nRT →V= nRT
p
V=
1mol(0.08206 mol L∙atm ∙ K)(373.15K )
1atm
V=30.621 L
Virial equation of state
yi ω T c(K) Zc V c(c m3/mol)
Methane (1) 0.33 0.012 190.6 0.286 98.6
Propane (2) 0.33 0.152 369.8 0.276 200
N-Pentane (3) 0.33 0.252 469.7 0.27 383
k
ij=1-
8(V CiV Cj)0.5
(V Ci 1 3 + V Cj 1 3 )3
k
ij i
1 2 3
j 1 0 0.020579 0.073256
2 0.020579 0 0.017401
3 0.073256 0.017401 0
T
Cij=(T CiT Cj)0.5(1-kij