Zinc sulfate

Zinc sulfate
IUPAC name Zinc sulfate
Other names White vitriol Goslarite
Identifiers
CAS number	7733-02-0 Y,  7446-19-7 (monohydrate) 13986-24-8 (hexahydrate) 7446-20-0 (heptahydrate)
PubChem	24424
ChemSpider	22833 Y
UNII	0J6Z13X3WO Y
EC number	231-793-3
UN number	3077
ChEBI	CHEBI:35176
ChEMBL	CHEMBL1200929
RTECS number	ZH5260000
Jmol-3D images	Image 1
SMILES [Zn+2].[O-]S([O-])(=O)=O
InChI InChI=1S/H2O4S.Zn/c1-5(2,3)4;/h(H2,1,2,3,4);/q;+2/p-2 Y Key: NWONKYPBYAMBJT-UHFFFAOYSA-L Y InChI=1/H2O4S.Zn/c1-5(2,3)4;/h(H2,1,2,3,4);/q;+2/p-2 Key: NWONKYPBYAMBJT-NUQVWONBAU
Properties
Molecular formula	ZnSO4
Molar mass	161.47 g/mol (anhydrous) 179.47 g/mol (monohydrate) 287.53 g/mol (heptahydrate)
Appearance	white powder
Odor	odorless
Density	3.54 g/cm3 (anhydrous) 2.072 g/cm3 (hexahydrate)
Melting point	680 ºC decomp. (anhydrous) 100 °C (heptahydrate) 70 °C, decomp (hexahydrate)
Boiling point	740 °C (anhydrous) 280 °C, decomp (heptahydrate)
Solubility in water	57.7 g/100 mL, anhydrous (20 °C)[1]
Solubility	alcohols
Refractive index (nD)	1.658 (anhydrous), 1.4357 (heptahydrate)
Hazards
MSDS	ICSC 1698
EU Index	030-006-00-9
EU classification	Harmful (Xn) Dangerous for the environment (N)
R-phrases	R22, R41, R50/53
S-phrases	(S2), S22, S26, S39, S46, S60, S61
Flash point	Non-flammable
Related compounds
Other cations	Cadmium sulfate
Related compounds	Copper(II) sulfate
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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.^[2]

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 SO₄^2- 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.

Applications

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. 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 an astringent and emetic.^[2]

Minerals

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).

References

1. ^ Lide, David R., ed (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3. 
2. ^ ^{a b} Dieter M. M. Rohe, Hans Uwe Wolf "Zinc Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a28 537