The adiabatic compressibilities of concentrated metal-ammonia solutions.

Abstract

Concentrated solutions of the alkali and alkaline earth metals in liquid ammonia possess pronouncedly metallic properties whereas the dilute solutions, blue in color, display typically electrolytic properties. These solutions over their whole range of concentration have been extensively investigated by C.A. Kraus and co-workers with the result that a considerable body of empirical information regarding the solutions at hand. The concentrated region, between 40 moles NH3/g atom metal and saturation (6/1 for sodium, 4/1, for lithium, etc) has an electrical conductivity that increases over a thousand-fold between these limits to a value at saturation of the same order of magnitude found for metals. Over this range a marked drop in viscosity is observed, the value at saturation being 0.140 cp as against the value 0.230 at about 50/1. formation of the solutions fron the constituents is accompanied by large volume effect with a maximum of 43cc. at about 11/1. With regard to the magnetic properties the concentrated solutions are found to possess a degenerate paramagnetic susceptibility quite similar to the alkali metals themselves. Finally, evidence of the metallic nature of these solutions appears from the results of photo-electric studies which show a surface effect. [TRUNCATED]