Zinc Sulphate heptahydrate 21% agricultural Grade 1)ZnSO4.7H2O%,98%;Zn,22% ... ,50kg/bag 3)Use,minerals&trace element Zinc Sulphate heptahydrate 21% agricultural GradeMolecular Formula: ZnSO4. (x) H2O (x=1 ... in water, insoluble in ethanol, aqueous solution is acidic;.pH=4.5,the appearance of monohydrate zinc sulphate is ... 95-Feed grade standard: 2934-2000 Zinc Sulphate heptahydrate 21% agricultural Grade