Zinc sulfate

Zinc sulfate
Names
IUPAC name
Zinc sulfate
Other names
White vitriol
Goslarite
Identifiers
ATC code A12CB01
7733-02-0 Yes
7446-19-7 (monohydrate) 
13986-24-8 (hexahydrate) 
7446-20-0 (heptahydrate) 
ChEBI CHEBI:35176 Yes
ChEMBL ChEMBL1200929 
ChemSpider 22833 Yes
EC number 231-793-3
Jmol-3D images Image
PubChem 24424
RTECS number ZH5260000
UNII 0J6Z13X3WO Yes
UN number 3077
Properties
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 °C (1,256 °F; 953 K) decomposes (anhydrous)
100 °C (heptahydrate)
70 °C, decomposes (hexahydrate)
Boiling point 740 °C (1,360 °F; 1,010 K) (anhydrous)
280 °C, decomposes (heptahydrate)
57.7 g/100 mL, anhydrous (20 °C)[1]
Solubility alcohols
1.658 (anhydrous), 1.4357 (heptahydrate)
Thermochemistry
120 J·mol−1·K−1[2]
Std enthalpy of
formation (ΔfHo298)
 −983 kJ·mol−1[2]
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 sulfateManganese sulfate
Related compounds
 Copper(II) sulfate
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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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.[3]

It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.[4]

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.[5]

Solubility only applies in acidic solutions.

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. Zinc sulfate, like many zinc compounds, can be used to control moss growth on roofs.[6] 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.[3]

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).

Safety

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. [7]

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. ↑ 2.0 2.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 0-618-94690-X.
  3. ↑ 3.0 3.1 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
  4. ↑ "WHO Model List of EssentialMedicines" (PDF). World Health Organization. October 2013. Retrieved 22 April 2014.
  5. ↑ "Zinc Sulphate Zinc Sulfate MSDS Sheet of Manufacturers". Mubychem.com. 2013-05-05. Retrieved 2013-06-08.
  6. ↑ "Moss on Roofs," Community Horticultural Fact Sheet #97, Washington State University King County Extension,
  7. ↑ European Food Safety Authority (EFSA), "Scientific Opinion on safety and efficacy of zinc compounds (E6) as feed additives for all animal species: Zinc sulphate monohydrate", Feb 2012