Beryllium evaporation studies

Solutions of alkali metals in ammonia have been the best studied, but other metals and other solvents give similar results. The alkaline earth metals except- beryllium form similar solutions readily, but upon evaporation a solid ammoniste. M(NHJ)jr, is formed. Lanthanide elements with stable +2 oxidation states (europium, ytterbium) also form solutions. Cathodic reduction of solutions of aluminum iodide, beryllium chloride, and teUraalkybmmonium halides yields blue solutions, presumably containing AP+, 3e Be2, 2e and R4N, e respectively. Other solvents such as various amines, ethers, and hexameihytphosphoramide have been investigated and show some propensity to form this type of solution. Although none does so as readily as ammonia, stabilization of the cation by complexation results in typical blue solutions... 

The vapor pressure of beryllium and the effect of oxide and nitride films of various thicknesses were studied, using Langmuir s method. According to Langmuir, the vapor pressure P in atmospheres is related to the rate of evaporation m in grams per square centimeter per second at the absolute temperature T by the formula... 

Beryllium has very little tendency to form acid salts and only an acid oxalate, an acid molybdate, an acid phosphate, an acid arsenate and four acid selenites have place in chemical literature. The first has been shown to be a simple mixture of the normal oxalate and oxalic acid, and tlie molybdate and selenites were little more than the residues left on evaporating the constituents with little of detail in their study. The phosphate was non-crystalline. These salts need confirmation although from the well known tendencies of phosphoric acid, the existence of an acid phosphate would seem as probable as any acid salt of beryllium. 

Anunoninm Beryllium Fluoride, BeF2.2NH F.—First prepared by Marignac, (1873 2) and later studied by v. Helmholt (1893 2) and Lebeau (1899 ii). Obtained by evaporating the constituents as small colorless needles or rhombic prisms. It is isomorphous with the corresponding potassium salt. Lebeau used it as a means to prepare pure beryllium fluoride Marig c figures the crystals and gives full measurements. 

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