Zinc Sulphate Mono Hydrate) – Powder (ZnSo4.H2O) - 33% Zn Min. w/w : Powder form of Mono Zinc (33% Zn) is compatible with urea it also increases the efficiency of urea by chelating the urea pills as a coating agent. Shelf life and storage is very good than zinc sulphate heptahydrate (21% Zn)..