Nickel(II) acetate tetrahydrate, min. 97,5 %, extra pure, Molar mass (M) 248,86 g/mol, Density (D) 1,74 g/cm³, CAS No. [6018-89-9], UN-Nr. 3077, EG-Nr. 611-946-4, Empirical formula C4H6NiO4 4 H2O