Description of polyatomic real substances by two-center Lennard-Jones model fluids
1986; Elsevier BV; Volume: 25; Issue: 3 Linguagem: Inglês
10.1016/0378-3812(86)80001-2
ISSN1879-0224
AutoresMichael Bohn, Rolf Lustig, Johann Fischer,
Tópico(s)Chemical Thermodynamics and Molecular Structure
ResumoBohn, M., Lustig, R. and Fischer, J., 1986. Description of polyatomic real substances by two-center Lennard-Jones model fluids. Fluid Phase Equilibria, 25: 251–262. For O2, CO, CS2, C2H4, Cl2 and Br2 orthobaric properties were calculated by perturbation theory on the basis of two-center Lennard-Jones (2CLJ) model molecules. The LJ-parameters σ and ε were determined by fitting the vapour pressure and the bubble density at one temperature about halfway between the triple point and 0.8 Tc. The elongation L in the model was fixed to give the correct temperature variation of the vapour pressure. The temperature variation of the orthobaric liquid density turned out to be less dependent on L, and could be satisfactorily reproduced. With the parameters determined from the orthobaric properties of the liquid, second virial coefficients were calculated. This was also done for Ar, Kr, Xe, CH4, N2, F2 and C2H6 for which the parameters have been determined previously in a similar way. The agreement between the predicted and the experimental second virial coefficients is excellent for C2H4 and C2H6. For O2, N2, CO and F2 it is still better than for the spherical molecules. The agreement for Cl2 and CS2 is less satisfactory.
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