Isotherms for the He-Ar system at -130, -115, and -90°C up to 700 atm

Provine, J.A.; Canfield, F. B.

doi:10.1016/0031-8914(71)90038-3

Cited by 33 publications

(18 citation statements)

References 7 publications

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“…Once more, for the integration of the ODE system, we fitted the data for the acoustic virial coefficients in Table 3 and obtained the following functions: [34], empty square [35], solid circles [36], empty circles [31], up-pointing solid triangles [37], uppointing empty triangles [32], solid diamonds [38], empty diamonds [39], down-pointing solid triangles [33], downpointing empty triangles [40], clubs [41], stars [42], crosses [2], hearts [43] spades [44]. The solid lines indicate the uncertainty of C num .…”

Section: Determination Of Acoustic and Pvt Virialmentioning

confidence: 99%

High-precision virial coefficients of argon and carbon dioxide from integration of speed of sound data in the pressure–temperature domain

2012

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Section: Determination Of Acoustic and Pvt Virialmentioning

confidence: 99%

High-precision virial coefficients of argon and carbon dioxide from integration of speed of sound data in the pressure–temperature domain

2012

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“…November Figures 4 to 7 show the results obtained for the mixtures CH4-CF4 , Edmister, 1970), He-Ar (Blancett et al, 1970; Provine and Canfield, 1971), He-N2 (Hall and Canfield, 1970). …”

Section: Page 936mentioning

confidence: 94%

An equation for predicting third virial coefficients of nonpolar gases

Santis¹,

Grande²

1979

AIChE Journal

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An empirical correlation for calculating third virial coefficients of nonpolar gases is developed in agreement with the corresponding states theorem. This equation requires the use of a third parameter which can be estimated from molecular parameters. The method is reliable, even for systems where no experimental data are available. The extension to mixtures involves one interaction constant for all possible binary sets. SCOPEVolumetric and thermodynamic properties of gases and vapors can be conveniently estimated by the virial equation of state. The virial equation is normally used up to moderate pressures, since only data of second virial coefficients are plentiful in the literature. Indeed, several analytical methods have been developed for calculating second virial coefficients (Tsonopoulos, 1974; Hayden and OConnell, 1975;Tarakad and Danner, 1977). However, the advantages of the virial equation could be increased if quantitative information were available on the third virial coefficient.Calculations of the third virial coefficients with intermolecular potential functions cannot be carried out with sufficient accuracy because of the present uncertainties on the real potential functions and on their nonpairwise additivity corrections. Empirical correlations are more useful. The only one available is that of Chueh and Prausnitz (1967) which, however, does not allow calculations in the absence of data.This work provides a predictive method based on the available data and on recent advances in the theoretical estimates of the third virial coefficient. CONCLUSIONS AND SIGNIFICANCEA successful correlation for predicting the third virial coefficients of pure and mixed nonpolar gases in temperature ranges of practical interest has been developed. The equation is in agreement with the corresponding states theorem and requires a knowledge of the critical volume and temperature, acentric factor, dipole polarizability, and molecular volume of the compounds involved. A binary interaction constant is also required to extend the method to mixtures. The correlation is a reliable predictive method of the third virial coefficients as shown by comparisons with experimental data.The main significance of this work concerns the possibility of extending the virial equation up to about threefourths of the critical density to calculate fugacity coefficients. These are required to interpret multicomponent vapor-liquid and gas-liquid equilibria at high pressures. where B, the second virial coefficient, is related to the potential energy between two molecules; C, the third virial coefficient, is related to the interaction energy among three molecules, etc. The theoretical calculations of C for various gases are hindered by the uncertainties about the real form of binary intermolecular potentials and about the nonpairwise additivity contributions. Simple POtential functions with two or three parameters do not allow accurate calculations, even if several three-body contributions are taken into account (De Santis and Grande, 1979).

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“…Curve 1, present potential (with triple dipole term) ; curve 2, BFW potential (with triple dipole term) ; curve 3, present potential (assuming pair additivity); curve 4, BFW potential (assuming pair additivity). Experimental data : O, [11] ; (~, [12] ; @, [13] ; ~, [14]. Figure 4 shows percentage deviations of the calculated viscosity coefficients from the smoothed data of Maitland and Smith [15].…”

Section: Consistency Of the Potential With Experimental Datamentioning

confidence: 98%

“…These deviations, as well as those obtained using t the BFW potential, are within experimental errors. Figure 3 shows the experimental [11][12][13][14] and calculated third virial coefficients. The results for the BFW potential are given as well.…”

Section: Consistency Of the Potential With Experimental Datamentioning

confidence: 99%

A pair potential for argon determined from thermodynamic properties of the dense gas

Malijevský

Labı́k

1982

Molecular Physics

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A data inversion technique is proposed for the determination of pair interatomic potentials from the Helmholtz free energies of a dense gas, and a potential for argon is determined. The reliability of the potential is tested by comparing the theoretical and the experimental results for the second and third virial coefficients, viscosity coefficients, and the thermodynamic properties of the liquid. With the exception of the viscosities, our potential predicts these properties as well or better than that of Barker, Fisher and Watts.

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Isotherms for the He-Ar system at -130, -115, and -90°C up to 700 atm

Cited by 33 publications

References 7 publications

High-precision virial coefficients of argon and carbon dioxide from integration of speed of sound data in the pressure–temperature domain

High-precision virial coefficients of argon and carbon dioxide from integration of speed of sound data in the pressure–temperature domain

An equation for predicting third virial coefficients of nonpolar gases

A pair potential for argon determined from thermodynamic properties of the dense gas

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