The salt is usually obtained as a by-productof copper refining. It is also produced bydissolution of nickel metal or nickel oxides in sulfuric acid.
Aqueous solutions of nickel sulfate reacts wit hsodium carbonate to precipitate nickel carbonate, a precursor to nickel-based catalysts and pigments. Addition of ammonium sulphate to concentrated aqueous solutions of nickel sulfateprecipitates Ni(NH4)2(SO4)2Â·6H2O. This blue-coloured solid is analogous to Mohr's salt,Fe(NH2(SO4)2Â·6H2O.
Nickel sulfate is used in the laboratory. Columnsused in polyhistidine-tagging, useful in biochemistry and molecularbiology, are regenerated with nickel sulfate. Aqueous solutions ofNiSO4Â·6H2O and related hydrates react with ammonia to give [Ni(NH3)6]SO4 and with ethylenediamine togive [Ni(H2NCH2CH2NH2)3]SO4. The latter is occasionally used as a calibrant for magnetic susceptibility measurementsbecause it has no tendency to hydrate.