ZnSO4.7H2O is a white hydrated crystal. Its density is 3.31 g/cm³, deliquescent in air. It disolves well in water. ZnSO4.7H2O loses crystal water at 280 ̊C:
• ZnSO4.7H2O = ZnSO4 + 7H2O(g)

ZnSO4 Decomposes at 500 ̊C
• ZnSO4 = ZnO + SO3(g)

ZnSO4.7H2O Usage: used in agriculture as animal feed additives, fertilizer and pesticide for fruit tree; for preparation of other zinc salts, lithopone, viscose and vinylon fiber etc.