... High purity 100% water soluble Base fertilizer Ammonium sulphate 21 fertilizertech garde 21%(AS/SOA)Molecular Formula:(NH4)2SO4, Molecular Weight:132 ... .13,Appearance: white crystals, N: 21% min;Free acid as H2SO4:0.03% max,Moisture:0 ... visible mechanical impurityno visible mechanical impurityN content(dry basis),% ≥21.021.020.5Water content(H2O),% 0.20.31.0Free acid ...