The equation of state of a gaseous mixture

Abstract

The methods of determining intermolecular fields, which have been used in former papers,* apply only to molecules of the same kind. This paper considers the more general problem of determining the forces between molecules of different kinds. It shows that this information can be derived from a study of the equation of state of binary mixtures, provided that the experimental work covers a sufficiently wide range of temperature and deals with mixtures of sufficiently varied proportions. The experimental information available at present is somewhat scanty and needs considerable extension. Apart from the earlier measurements of Amagat, the only available work on gaseous mixtures appears to be that of Holborn and Olto on a mixture of helium and neon, that of Verschoyle on a mixture of hydrogen and nitrogen, and that of Masson and Dolley on binary mixtures of ethylene, argon and oxygen. The former carried out experiments on a mixture of one proportion only, but have supplemented the results with further work on helium alone and neon alone, in each case covering the range of temperature 0 to 400° C. This work provides just enough data for the purpose of this paper, and from it the field between a helium atom and a neon atom, as well as the fields between two helium atoms and two neon atoms, can be deduced.