... , PH value: 9-9.5, the solubility is 28% , the density is 2.633 Sodium SulfiteMolecular formula:Na2SO3properties:White crystal or powder ... , crystal form, PH value: 9-9.5, the solubility is 28 ... %Water insoluble substance≤0.003%Free alkali≤0.40% Anhydrous sodium sulfite