monoclinic crystal,used in fixers, plating, leather, reductant, dechlorinating agent. 1, Chemical name: Sodium thiosulfate 2, Structural formula:3, Molecular formula: Na2S2O2·5H2O4, Molecular weight: 248.175, Properties: monoclinic crystal, Melting point : 40-45, Relative density :1.729(17). 6, Quality standard:Item Photo gradeTech gradeAnhydrous gradeAppearancecolorless transparent crystal ...