Zinc sulfate

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Zinc sulfate
Zinc sulfate crystals.jpg
Zinc sulfate obtained by reducing CuSO4 with Zn metal
IUPAC name
Zinc sulfate
Other names
White vitriol
Zinc(II) sulfate
Molar mass 161.47 g/mol (anhydrous)
179.47 g/mol (monohydrate)
287.53 g/mol (heptahydrate)
Appearance White solid
Odor Odorless
Density 3.54 g/cm3 (anhydrous)
2.072 g/cm3 (hexahydrate)
Melting point 680 °C (1,256 °F; 953 K) decomposes (anhydrous)
100 °C (212 °F; 373 K) (heptahydrate)
70 °C (158 °F; 343 K) decomposes (hexahydrate)
Boiling point 740 °C (1,360 °F; 1,010 K) (anhydrous)
280 °C (536 °F; 553 K), decomposes (heptahydrate)
57.7 g/100 mL (25 °C)
101 g/100 ml (70 °C)
Solubility Insoluble in ethanol, toluene
Vapor pressure ~0 mmHg
120 J·mol−1·K−1
Safety data sheet LabChem (heptahydrate)
Flash point Non-flammable
Related compounds
Related compounds
Cadmium sulfate
Mercury(II) sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Zinc sulfate (also known as white vitriol) is the inorganic compound with the chemical formula ZnSO4. It is a common source of the zinc ion, and is colorless and water soluble.



Zinc sulfate will react with sodium carbonate to yield sodium sulfate and zinc carbonate.

ZnSO4 + Na2CO3 → ZnCO3 + Na2SO4

At temperatures over 680 °C, zinc sulfate decomposes to yield sulfur trioxide gas and zinc oxide fumes.

ZnSO4 → ZnO + SO3


Zinc sulfate is a white hygroscopic solid. It is soluble in water and some alcohols. It forms three hydrates.


Zinc sulfate heptahydrate can be found in nature as the mineral known as goslarite.

Zinc supplements generally contain zinc sulfate, usually mixed with vitamins or sweeteners and are available at pharmacies.

Lastly, it can also be bought from chemical suppliers.


A simple way to make zinc sulfate is to react sulfuric acid with zinc metal.

Zn + H2SO4 → ZnSO4 + H2

Since this reaction releases highly flammable hydrogen, zinc oxide, hydroxide or carbonate can also be used instead.

Zinc sulfate can be prepared by adding zinc metal to a solution of copper(II) sulfate. Metallic copper sponge will precipitate (with small amounts of copper(II) oxide and copper(I) oxide) and the solution will become colorless when the reaction stops. The filtered solution can be boiled to crystallize the zinc sulfate from the solution.




Zinc sulfate has low toxicity and is also sold as a supplement. It's best to avoid consuming lab-grade ZnSO4 though, as it may contain traces of heavy metals (cadmium e.g.). Anhydrous zinc sulfate may cause irritations.


The anhydrous form should be stored in closed bottles to prevent hydration. Otherwise there are no special procedures needed.


If not contaminated with heavy metals or other toxins, it can be safely dumped in the ground or down the drain.

You can also recover the zinc metal through electrowinning. The leftover acidic solution should be neutralized before disposal.


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