Some comments on `Equation for the second virial coefficient`

TL;DR

This paper critically evaluates a proposed equation for the second virial coefficient, showing it fails to accurately match experimental data across various gases and temperatures, contradicting prior derivations.

Contribution

The paper provides a comprehensive comparison of the proposed formula with experimental data, demonstrating its limitations and inaccuracies for multiple substances.

Findings

The formula does not match experimental data within error margins.

It cannot accurately describe temperature dependence of the second virial coefficient.

The formula contradicts previous theoretical derivations.

Abstract

The second viral coefficient calculated using the equation suggested in the paper of Kaplun A.B., Meshalkin A.B. Equation for the second virial coefficient published in High temperature high pressure, 1999, Volume 31, pages 253-258 is compared with experimental data for helium, hydrogen, neon, argon, krypton, xenon, carbon dioxide, water, ammonia, methane, ethylene. It is shown the formula cannot describe the temperature dependence of the experimental data on the second virial coefficient for the all above substances within the experimental error over the investigated temperature interval. The latter is in controversy with the derivations of the paper mentioned above. It is also shown the formula cannot describe the recommended data for the second virial coefficient within their uncertainties for helium, hydrogen, neon, argon, krypton and methane.