Beryllium salt

Beryllium salts rapidly hydrolyse in water to give a series of hydroxo complexes of undetermined structure the equilibria depend... 

The observed inter-atomic distances (Table XIX) for the beryllium salts are somewhat smaller than those calculated. This indicates that there is more deformation in these crystals than in the sodium chloride type crystals, despite the smaller effective nuclear charge of the two-shell cation and points to the existence of an increased tendency to deformation... 

Skin contact with soluble beryllium salts may produce either primary irritation or sensitization dermatitis characterized by pruritis... 

Beryllium sulfate may be prepared by treating an aqueous solution of any beryllium salt with sulfuric acid, followed by evaporation of the solution and... 

Beryllium Diazide (formerly called Beryllium Trinitride), Be(Ns)j mw 93 07, N 90.31% wh solid, sol in tetrahydrofuran, insol in eth and easily hydrolyzed by w(Ref 1). Obtd by Wiberg Michaud (Ref 4) when Me,Be was sublimed and reacted with a dry eth soln of excess HNS at -116°. Removal of eth and excess HNS by vac distn yielded Be(N,),. In a reactn betw a beryllium salt and an azide, Curtius Rissom (Refs 1 2) obtd an impure beryllium azide it detonated only si in a flame and is insensitive to initiation by percussion (Ref3)... 

Beryllium Carbonates. Beryllium carbonate tetrahydrate [60883-64-9], BeC03 4H20, has been prepared by passing carbon dioxide through an aqueous suspension of beryllium hydroxide. It is unstable and is obtained only when the solution is under carbon dioxide pressure. Beryllium oxide carbonate [66104-25-4] is precipitated when sodium carbonate is added to a beryllium salt solution. Carbon dioxide is evolved. The precipitate appears to be a mixture of beryllium hydroxide and the normal carbonate, BeC03, and usually contains two to five molecules of Be(OH)2 for each BeC03. 

Beryllium Metavanadate, Be(V03)2.4H20.—Addition of solutions of beryllium salts to alkali vanadates gives rise to basic vanadates of indefinite composition. The pure salt is obtained by boiling beryllium hydroxide and vanadium pentoxide in water in the required proportions. The solution is filtered, concentrated to a syrup and poured into alcohol, whereupon isometric cubes, modified by an octahedron, are obtained. The larger crystals polarise light. Density, 2-273. One gram dissolves in a litre of water at 25° C.s... 

NHj and CO2 and precipitates a high-purity, basic beryllium carbonate. If the aqueous system has the stoichiometry of (NtL Be COi) , analogous to the ammonium nranyl carbonate system, the basic beryllium carbonate product of hydrolysis is 2BeCC>3 Be(OH)2- This compound is readily dissolved in all mineral acids, making it a valuable starting material for laboratory synthesis of beryllium salts of high purity. 

Beryllium hydroxide, [CAS 13327-32-7], Be(OH)2 is precipitated as an amorphous, gelatinous material by addition of ammonia or alkali to a solution of a beryllium salt at slightly basic pH values. A pure hydroxide can be prepared by pressure hydrolysis of a sluriy of beryllium basic carbonate in water at 165°C. All forms of beryllium hydroxide begin to decompose in air or water to beryllium oxide at 190c C. 

Basic beryllium acetate, [CAS 543-81-7], Be40(C2lL02)6, is the best known of the beryllium salts of organic adds which can be divided into normal beryllium carboxylates, Be(RCOOh. and beryllium oxide carhoxylates, Re40(RC.00). The basic aceiate is soluble in glacial acetic acid and can readily be crystallized therefrom in very pure form. It is also soluble in chloroform and other organic solvents. It has been used as a source of pure beryllium salts,... 

Acute pulmonary disease is due exclusively to inhalation of soluble beryllium salts and is not caused by exposure to the oxide, the metal, or its alloys. The exact forms of beryllium causing the chronic pulmonary disease and the degree of exposure necessary to induce it are not precisely known. It is known that under the completely uncontrolled conditions existing in bery llium extraction plants before the establishment of air-count standards in 1949, when beiyllium air-counts were in milligrams per cubic meter of air rather than micrograms, only about 1% of the exposed workers became ill This would indicate a sensitivity of a limited number of individuals to beryllium. 

A first requirement for a substance to produce a taste is that it be water soluble. The relationship between the chemical structure of a compound and its taste is more easily established than that between structure and smell. In general, all acid substances are sour. Sodium chloride and other salts are salty, but as constituent atoms get bigger, a bitter taste develops. Potassium bromide is both salty and bitter, and potassium iodide is predominantly bitter. Sweetness is a property of sugars and related compounds but also of lead acetate, beryllium salts, and many other substances such as the artificial sweeteners saccharin and cyclamate. Bitterness is exhibited by alkaloids such as quinine, picric acid, and heavy metal salts. 

The salty taste is best exhibited by sodium chloride. It is sometimes claimed that the taste of salt by itself is unpleasant and that the main purpose of salt as a food component is to act as a flavor enhancer or flavor potentiator. The taste of salts depends on the nature of both cation and anion. As the molecular weight of either cation or anion— or both—increases, salts are likely to taste bitter. The lead and beryllium salts of acetic acid have a sweet taste. The taste of a number of salts is presented in Table 7-4. 

Quinalizarin reagent cornflower-blue colouration with faintly alkaline solutions of beryllium salts. The reagent alone gives a characteristic violet colour with dilute alkali but this is quite distinct from the blue of the berryllium complex a blank test will render the difference clearly apparent. 

Acetylacetone test Acetylacetone reacts with beryllium salts to yield the... 

Dry test Upon heating beryllium salts with a few drops of cobalt nitrate solution upon charcoal a grey mass is obtained (difference from aluminium). 

The addition of soluble carbonates to beryllium salt solutions gives only basic carbonates. Beryllium salt solutions also have the property of dissolving additional amounts of the oxide or hydroxide. This behavior is attributable to the formation of complex species with Be—OH—Be or Be—O—Be bridges. The rapidly established equilibria involved in the hydrolysis of the [Be(H20)4]2+ ion are very complicated and depend on the anion, the concentration, the temperature, and the pH. The main species, which will achieve four-coordination by additional water molecules, are considered to be Be2(OH)3+ and Be3(OH)3+ (probably cyclic). 

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