TYPICAL PREP FOR CUPROUS BROMIDE
Cuprous bromide can be prepared by dissolving 600 g. (2.4 moles) of commercial copper sulfate crystals and 350 g. (3.4 moles) of sodium bromide in 2 l. of warm water; the solution must be stirred while 151 g. (1.2 moles) of solid sodium sulfite are added over a period of 10 minutes.
Occasionally a little more sodium sulfite may be required to discharge the blue color. The mixture must be cooled, and the solid collected on an 8-in. Büchner funnel, washed once with water, pressed nearly dry, and then dried in the air overnight. The yield of cuprous bromide should be approximatly 320 g. (93%).
Additionally,Cuprous bromide can be generated by dissolving copper powder in hydrobromic acid:
2 HBr + 2 Cu → 2 CuBr + H2
The CuBr, copper(I) bromide salts are produced by boiling an acidic solution of copper(II) ions in an excess of copper. Upon dilution, pale yellowCuBr is produced.
CuBr is a diamagnitic solid which adopts a polymeric structure similar to zinc sulfide (four-coordinated, tetrahedral Cu centers interconnected by bromide ligands). CuBr is often used in the synthesis of organic compounds.
The method used to prepare the salt depends upon the solubility of the salt. Since all acids are aqueous solutions the acid needed does not effect the method of preparation.