The thermochemistry of calcium strontium and barium in liquid ammonia at -33°C.

• Main Author: Wolsky, Sumner Paul
• Language: en_US
• Published: Boston University 2014
• Online Access: https://hdl.handle.net/2144/9330

Thesis (Ph.D.)--Boston University === The solutions of the alkali and alkaline earth metals in liquid ammonia are characterized by certain anomalous properties which are generally similar for these groups of metals. The similarity of the properties of these metal-ammonia solutions has been found to be due to the presence of a common negative species, the electron associated with the solvent in some undetermined manner (the "solvated" electron). In this dissertation the investigations of the ammonia solutions of the alkaline earth metals have been reviewed. Early studies have indicated that calcium, strontium, and barium metals combine with ammonia to form their respective hexammoniates, M(NH3)6. The heats of formation of these compounds, as determined from vapor pressure data, are: - 10.3 kcal.,- 9.9 kcal., and - 9.6 kcal., respectively. Magnesium metal, which is only sparingly soluble in liquid ammonia, also forms a hexammoniate. The following general remarks can be applied to all the alkaline earth metal ammoniates: the compounds a re identical in appearance with the solutions from which they are precipitated; the optical and electrical properties are the same for both the solid and the solution, therefore being independent of the physical state of the system and probably being determined by the same factors.