Product description: CAS No.: 7681-57-4 Molecular Formula: Na2S2O5 Molecular Weight: 190.10 White or light yellow crystalline powder , relative density is 1.4 . Soluble in water (when 20°C, 54g/100ml water; when 100°C,81.7g/100ml water), acidic aqueous solution. Soluble in glycerine,slightly soluble in ethanol. Moisture easily decomposed, exposed in the air easily oxidized into sulfate. Exposure to emit sulfur dioxide and acid generated the corresponding salts. Heated to 150°C decomposition.