Synonym: Sodium hyposulfite; Sodium subsulfite Molecule Formula: Na2S2O3 ·5H2O Molecular Weight: 248 CAS No. : 7772-98-7 Property: Colorless, transparent single oblique crystals, specific gravity: 1.729. It’s soluble in water easily, with strong reducing property. Specification: GradePhotoTechNa2S2O3·5H2O99% Min99.0% MinWater Insoluble Matter 0.01% Max0.01% MaxNa2S0.001% Max0.001% MaxFe 0.002% Max0.002% MaxPH value (200g/L solution)6.5-9.56.5-9.5 Packing : Net each in 25kg plastic woven bag, lined with PE bag. Usage: Used in photographic, electroplate, purifying soft water and tanning processing hides, it also can be used as reducing agent, deoxidizer, sulfur dyeing agent, anti-white agent, detergent, disinfectant and color coat agent, etc.