... .51% Min 3)ZnSO4:98%,99%Min 4)Appearance:White crystal powder,granular Food Grade Zinc Sulfate Heptahydrate 1) Physical and ... ZnSO4 7H2OMolecular weight 287.56Physical and chemical propertyWhite or slight-yellow crystal, loose and no agglomeration, easy soluble in water and slightly ... 280, it will become no water substance and lose all crystal water. When the temperature is above 500, it will decompose ...