kalfoglou_1967#
N. K. Kalfoglou and J. G. Miller, “Compressibility of Gases. V. Mixtures of Spherically Symmetric Molecules at Higher Temperatures. The Helium-Argon and Helium-Tetrafluoromethane Systems”, J. Phys. Chem. 71, 1256 (1967)
Source record · Catalogue · Review register
DOI: 10.1021/j100864a012
Source kind: measurement
Recorded technique: Burnett method (University of Pennsylvania; the apparatus of Witonsky and Miller 1963, their ref. 4), the volumes outside the principal bath thermostated at 30 C, an oil manometer in parallel with a Ruska 2406 diaphragm indicator for the final balance (pressures reproducible to 1 part in 20 000 down to 5 atm), the gas mixed in the first chamber by a magnetically driven steel ball. He (99.99 % by weight) and Ar (99.998 %) from Matheson. Isotherms at 30, 100, 200, 300, 400 and 500 C, nine equally spaced compositions including the pure gases, 3-80 atm in 11 expansions for He-Ar. Each run reduced by Harper and Miller’s method (their ref. 2): Z = exp(alpha p + beta p^2), with a delta p^4 term for pure Ar at 30 C, so that the pressure-series B = alpha (atm^-1). B_He-Ar from a least-squares fit of each isotherm’s nine B_mix to Eq. (4), B_mix = B_11 x_1^2 + 2 B_12 x_1 x_2 + B_22 x_2^2.
Materials in structured entries: Ar
Dataset quantities: cross_second_virial_coefficient
Contents: 1 dataset; 0 formulas.
Curation notes#
Identity VALIDATED_WITH_WARNINGS by the library: the DOI was asserted by the curator, and the library’s title check failed only because the observed title was cut at the first line. The page (pdf page 1, image checked) prints the full title as in the citation, page 1256, and ‘Volume 71, Number 5 April 1967’ in the footer of p. 1257; Crossref’s title misspells ‘tetafluoromethane’. Received August 8, 1966. Printed pp. 1256-1264 (pdf pages 1-9).
TABLE II (p. 1258, image checked against the cells file, 2026-10-01, every cell agreeing): B_He-Ar, present work, at 30-500 C in atm^-1 x 10^4 and in cc/mole, each with its probable error, and Tanner and Masson’s 18.50 (graphical interpolation) and 19.68 cc/mole at 30 and 100 C. Extracted: the cc/mole column, one dataset filed under Ar with the partner He (Ar sorts first). The atm^-1 column is the pressure-series coefficient B/(RT), a unit the vocabulary does not hold; Tanner and Masson’s values are another source’s (Proc. Roy. Soc. A126, 268 (1930), their ref. 10, not in the library).
NOT EXTRACTED, for want of a unit in the vocabulary: Table I (p. 1258), B_mix x 10^4 (atm^-1) and C_mix x 10^7 (atm^-2) of He-Ar at nine helium mole fractions and six temperatures (image checked; the mixture data proper), and Tables III and IV (p. 1259), the pure-gas B of He and Ar in atm^-1 (pure gas, and the intercepts of Eq. (4)). The paper prints no Z. The helium-tetrafluoromethane system (Tables V-VII, XI) is not extracted: CF4 is not an optmat gas. Tables VIII-X are fitted potential parameters.
REPRODUCED (computed 2026-10-01): the cc/mole column from the atm^-1 column times RT (R = 82.0574 cm^3 atm/(mol K), T = t + 273.15 K): 18.766, 19.734, 20.259, 20.449, 20.349 and 19.750 against the printed 18.77, 19.73, 20.26, 20.45, 20.35 and 19.75. Table I’s B_mix fitted by unweighted least squares to Eq. (4) at each temperature give B_12 = 7.544, 6.444, 5.217, 4.349, 3.684 and 3.113 x 10^-4 atm^-1 (printed 7.544, 6.445, 5.218, 4.348, 3.684, 3.113), and intercepts within 0.02 x 10^-4 atm^-1 of the ‘Mixtures’ columns of Tables III and IV (He at 30 C, 4.61 against 4.63).
UNCERTAINTY: ‘the errors given for the virial coefficients are probable errors determined from the least-squares fit of the observed B_mix values to the Lennard-Jones and Cook equation (eq 4)’ (p. 1258); the dataset takes them as printed, level probable error.
DOUBTS (computed 2026-10-01): - The level: the standard errors of the fit above are 0.070, 0.031, 0.053, 0.059, 0.036 and 0.046 x 10^-4 atm^-1 against the printed ‘probable errors’ 0.07, 0.03, 0.05, 0.05, 0.03 and 0.04; the fit’s probable errors (0.6745 times these) are 0.047, 0.021, 0.036, 0.040, 0.024 and 0.031. The printed values may be standard errors, which would make the dataset’s uncertainty 1.48 times too large. - The two columns’ uncertainties do not convert into each other: times RT, the atm^-1 ones give 0.17, 0.09, 0.19, 0.24, 0.17 and 0.25 cc/mole against the printed 0.10, 0.08, 0.2, 0.2, 0.3 and 0.3. The cc/mole ones are kept as printed. - A bias in the pure gases: Tables III and IV’s B times RT lie below CoolProp 8.0.0’s reference equations (Ortiz Vega et al. 2019 for He, Tegeler et al. 1999 for Ar): He by 0.2-0.8 cm^3/mol (pure gas: -0.43 at 30 C, -0.76 at 400 C), several probable errors; Ar by -0.49, -0.28 and -0.23 cm^3/mol at 30, 100 and 200 C, and within 0.2 above. If common to all compositions, a bias of this size is in B_12 too. - The experimental B_He-Ar of Table II are those of the measurements; the curve fits of the potentials (Figs. 3, 4, Table VIII) used them corrected for quantum effects (Lennard-Jones, Lambda* = 0.952), which the table does not include. - The temperature scale is not stated.
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
kalfoglou_1967/B12_He#
{
"id": "B12_He",
"material": "Ar",
"file": "Ar/kalfoglou_1967__B12_He.csv",
"table": "tbl_4e0de8840ac9",
"quantity": "cross_second_virial_coefficient",
"unit": "cm3/mol",
"abscissa": "temperature",
"abscissa_unit": "C",
"use": "primary",
"parameters": {
"partner": "He"
},
"uncertainty": {
"column": true,
"level": "probable error"
}
}
Table II (p. 1258): B_He-Ar of the present work in cc/mole, 30-500 C, with the printed probable errors; the atm^-1 cells and Tanner and Masson’s values stay in the printed column.
Formulas#
No formulas are recorded.
Corrections#
No dataset errata are recorded in this source record.
Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.