Sodium Sulfite Anhydrous

About This Product

Sodium sulfite has the formula Na2SO3 and CAS number 7757-83-7, supplied anhydrous as a white free-flowing powder, soluble in water and giving a mildly alkaline solution. It sits at the least acidic end of the sulfite range, and that is the basis on which it is selected. Sodium bisulfite and metabisulfite both drive pH downward as they dissolve and react, which is unhelpful in a boiler, where alkaline conditions are deliberately maintained to protect steel from acid corrosion. Sodium sulfite scavenges dissolved oxygen just as effectively, reacting with it to form sulfate, while leaving the carefully maintained boiler pH essentially undisturbed. Catalysed grades containing a cobalt accelerator react fast enough for use in low-temperature deaerators. Its other applications follow from the same reducing chemistry: it is a dechlorinating agent, an antioxidant in industrial processes, a reducing agent in dye chemistry and photographic developer, and a pulping chemical in the sulfite process. It is used in boiler feedwater oxygen scavenging, dechlorination, pulp and paper, photographic developing, textile processing and effluent treatment. Bio Green Chem supplies sodium sulfite to specification on assay, sulfate content, iron, insolubles, pH and heavy metals.