Zinc Sulfate Heptahydrate (ZnSO4·7H2O)

2015-6-29 5:56:37 Sulfates

Zinc sulfate is the inorganic compound with the formula ZnSO4 as well as any of three hydrates. It was historically known as "white vitriol". It is a colorless solid that is a common source of soluble zinc ions.

It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basichealth system.


Zinc Sulfate Heptahydrate crystal

Zinc Sulfate Heptahydrate - Supplied by Uniwin Chemical


Chemical Formula: ZnSO4·7H2O

IdentificationCAS: 7446-20-0


Physical and Chemical Characteristics (Typical):




White or Off-white Crystal Powder, easy to get cake

White or Off-white Granular or Prill

Particle Size


5-10mesh (1.7-4mm)


21.0% min

21~22.5% (to the request)


30ppm max

30ppm max


30ppm max

30ppm max


30ppm max

30ppm max



-          In pp bags with liner, 25kgs net each.

-          In jumbo bags, 1 ton or 1.25 tons net each.

-          Or as customer's requested.


Production and reactivity

Zinc sulfate is produced by treating zinc with aqueous sulfuric acid:

Zn + H2SO4 + 7 H2O → ZnSO4(H2O)7 + H2


Pharmaceutical grade zinc sulfate is produced from high purity zinc oxide:

ZnO + H2SO4 + 6 H2O → ZnSO4(H2O)7


In the laboratory, it can also be prepared by adding solid zinc to a copper(II) sulfate solution:

Zn + CuSO4 → ZnSO4 + Cu


In aqueous solution, all forms of zinc sulfate behave identically. These aqueous solutions consist of the metal aquo complex[Zn(H2O)6]2+ and SO42− ions. Barium sulfate forms when these solutions are treated with solutions of barium ions:

ZnSO4 + BaCl2 → BaSO4 + ZnCl2


With a reduction potential of -0.76, zinc(II) reduces only with difficulty.

When heated over 680 C, zinc sulfate decomposes into sulfur dioxide gas and zinc oxide fume, both of which are hazardous.

Solubility only applies in acidic solutions.


The hydrates, especially the heptahydrate, are the primary forms used commercially. The main application is as a coagulant in the production of rayon. It is also a precursor to the pigment lithopone. Zinc sulfate is used to supply zinc in animal feeds, fertilizers, and agricultural sprays. Zinc sulfate, like many zinc compounds, can be used to control moss growth on roofs. It is used as in electrolytes for zinc plating, as a mordant in dyeing, as a preservative for skins and leather and in medicine as anastringent and emetic.


As a mineral ZnSO4·7H2O is known as goslarite. Zinc sulfate occurs as several other minor minerals Zinc-melanterite(Zn,Cu,Fe)SO4·7H2O (structurally different from goslarite). Lower hydrates of zinc sulfate are rarely found in nature: (Zn,Fe)SO4·6H2O (bianchite ), (Zn,Mg)SO4·4H2O (boyleite), and (Zn,Mn)SO4·H2O (gunningite).


Zinc sulfate powder is an eye irritant. Ingestion of trace amounts is considered safe, and zinc sulfate is added to animal feed as a source of essential zinc, at rates of up to several hundred milligrams per kilogram of feed. Excess ingestion results in acute stomach distress, with nausea and vomiting appearing at 2-8 mg/Kg of body weight.