The chemical constant of chlorine vapour and the entropy of crystalline chlorine

Abstract

In a recent paper the writer calculated the vapour pressure of hydrogen crystals, using the Einstein-Bose statistics for the gaseous phase. The work was an extension of that of R. H. Fowler, who had used the slightly less accurate classical statistics for the hydrogen gas. In this paper we propose to apply similar methods of investigation to chlorine. The investigation will have to be different in some respects, however. Hydrogen was considered to consist of a mixture of two gases, para- and ortho-hydrogen, which retained their individuality over long periods of time at low temperatures. Due to the existence of two isotopes of chlorine, we shall here have five gases to consider instead of two. Further, hydrogen molecules almost certainly can rotate quite freely in the crystals of hydrogen; on the other hand, molecules of chlorine almost certainly can not rotate at all in crystals of chlorine.