The content of zinc sulfate depends on which form is used. The anhydrous, monohydrate, and heptahydrate forms of zinc sulfate are 41%, 36%, and 23% zinc by weight, respectively; therefore, 123 mg of anhydrous zinc sulfate, 137 mg of zinc sulfate monohydrate, and 220 mg of zinc sulfate heptahydrate each contain 50 mg of elemental …