Dissolve 88 g of sodium bromide in 500 mL of 40°C water with stirring, then add 150 g of copper sulfate pentahydrate. Then over the course of 5 minutes add 38 g of sodium metabisulfite and cool the mixture down in a freezer, filter and wash with 100 mL of cold water. Dry in a vacuum.
CuSO4 + 2 NaBr = CuBr2 + Na2SO4
2 CuBr2 + H2O + Na2SO3 = 2 CuBr + 2 HBr + Na2SO4
The bromide sulfate solution
Addition of the sodium metabisulfite
Filtering the mixture with washing
The dry product