Synonyms: Cobalt(II) sulfate heptahydrate, Cobaltous sulfate heptahydrate CAS: 10026-24-1 Molecular Formula: CoSO4 · 7H2O Molecular Weight: 281.10 g/mol Test Specification Cobalt (Co) 20.5% min. Nickel (Ni) 0.04% max. Manganese (Mn) 0.02% max. Iron (Fe) 0.01% max. Zinc (Zn) 0.003% max. Chromium (Cr) 0.004% max. Magnesium (Mg) 0.008% max. Copper (Cu) 0.002% max. Calcium (Ca) 0.002% max. Sodium (Na) 0.04% max. H2O Insolubles 0.03% max.