Sodium nitroprusside dihydrate, min. 99 %, p.a., ACS, Molar mass (M) 297,95 g/mol, Density (D) 1,71 g/cm³, CAS No. [13755-38-9], UN-Nr. 1588, EG-Nr. 238-373-9, Empirical formula Na2[Fe(CN)5NO] · 2 H2O