Iron(II) chloride tetrahydrate, min. 99 %, pure, Molar mass (M) 198,83 g/mol, Density (D) 1,93 g/cm³, CAS No. [13478-10-9], UN-Nr. 3260, EG-Nr. 231-843-4, Empirical formula FeCl2 · 4 H2O