Zinc Sulfate﹝ZnSO4·xH2O﹞contains one or seven molecules of water of hydration.The monohydrate contains not less than 89.0percent and not more than 90.4percent of ZnSO4,corresponding to not less than 99.0percent and not more than 100.5percent of ZnSO4·H2O,and the heptahydrate contains not less than 55.6percent and not more than 61.0percent of ZnSO4,corresponding to not less than 99.0percent and not more than 108.7percent of ZnSO4·7H2O.contact :jiaocai(at)hotmai(dot)com