Cadmium bromide

An example of a stepped isotherm, for krypton at 90 K, is shown in Fig. 2.21(a), where the adsorbent is graphitized carbon black, which is known to possess a very uniform surface. Figure 2.21(h) shows the steps obtained, also with krypton, on cadmium bromide. 

Fig. 2.21 Stepped isotherms of (a) krypton at 90 K on a carbon black graphitizcd at 2700°C. (a) (O) Run 1 ( ) Run 2 (b) krypton at 73-1 K on crystals of cadmium bromide. (Courtesy (a) Amberg, Spencer and Beebe " (b) Larher . )...

Cadmium Bromide. The hydrated bromide is prepared by dissolution of cadmium carbonate, oxide, sulfide, or hydroxide in hydrobromic acid. The white crystalline material is cadmium bromide tetrahydrate [13464-92-1], CdBr2 4H2O, Ai/ 29s —1492.55 kJ/mol (—356.73 kcal/mol) (3)... 

EFFECT OF QUATERNARY AMMONIUM SAET EXCHANGE CENTER STERIC ACCESSIBILITY ON EXTRACTION OF CADMIUM BROMIDE COMPLEXES... 

Thus, the QASes of the asymmetrical stmcture with improved steric accessibility of the exchange centre show the high selectivity to double-charged cadmium bromide complex ions relative to single-charged ions. 

Sandri (15) reported the formation of characteristic crystals with cadmium bromide-hydrobromic acid, bismuth iodide-potassium iodide, and bismuth bromide-hydrobromic acid, with compositions CdBr2 HBr CgHgN 4H 0, HBiI CgHoN, and HBiBr CgHgN, respectively. 

Cadmium bromide is used in hthography, engraving, and in the manufacture of photographic film. 

Cadmium bromide is prepared by heating cadmium with bromine vapor. Also the compound can be prepared by the treatment of dry cadmium acetate with glacial acetic acid and acetyl bromide. Alternatively, it may be obtained by dissolving cadmium or cadmium oxide in hydrobromic acid and evaporating the solution to dryness under hehum in an inert atmosphere. 

Cadmium bromide unites with ammonia, forming three compounds, namely, diammino-cadmium bromide, [Cd(NH3)2]Br2 triammino-cadmium bromide, [Cd(NH3)3]Br2 and tetrammino-cadmium bromide, [Cd(NH3)4]Br2. These correspond in chemical behaviour to the ammino-ehlorides. 

Diammino-cadmium Bromide, [Cd(NH3)2]Br2, is obtained in small colourless crystals by saturating a concentrated solution of cadmium bromide in water with ammonia and allowing the solution to evaporate. The compound is unstable and loses ammonia on heating, and on treatment with water is partially decomposed with formation of cadmium hydroxide. The same product is formed by saturating an acetone solution of cadmium bromide with ammonia gas.1... 

Triammino-cadmium Bromide, [Cd(NH3)3]Br2, is formed when ammonia gas is passed into an ammoniacal solution of cadmium bromide. It is a colourless crystalline substance which, on exposure to air, decomposes, the crystals becoming opaque and powdery. 

Tetrammino-cadmium Bromide, [Cd(NH3)4]Br2, is prepared by passing dry ammonia gas over dry powdered cadmium bromide. The salt swells up, absorbs ammonia, and is transformed into tetrammine. It is unstable, and on heating loses ammonia completely. If dissolved in water ammonia is eliminated and precipitation of cadmium hydroxide takes place. 

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