... at 135.1614.1213 Sodium Sulfite Anhydrous Purity from 90%-97% min.Appearance: white crystalline powder .Molecular formula : Na2SO3Packing : double-layer ... gradeFirst gradeSalable productIndustrial gradeSodium sulfite ( Na2SO3 ) , % ≥97.096.093.090.0Fe , ?≤0.0030.0050.01/Water insoluble matter , % ≤0.020.030.05 ... half year from ex-factory date. Sodium Sulphite anhydrous 90-97%