Chemistry:Manganese(II) sulfate

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Manganese(II) sulfate
Manganese(II) sulfate close-up.jpg
Manganese(II) sulfate monohydrate
Manganese(II)-sulfate-tetrahydrate-sample.jpg
Manganese(II) sulfate tetrahydrate
Names
IUPAC name
Manganese(II) sulfate
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
EC Number
  • 232-089-9
RTECS number
  • OP1050000 (anhydrous)
    OP0893500 (tetrahydrate)
UNII
Properties
MnSO4
Molar mass 151.001 g/mol (anhydrous)
169.02 g/mol (monohydrate)
223.07 g/mol (tetrahydrate)
277.11 g/mol (heptahydrate)
Appearance white crystals (anhydrous)
pale pink solid (hydrates)
Density 3.25 g/cm3 (anhydrous)
2.95 g/cm3 (monohydrate)
2.107 g/cm3 (tetrahydrate)
Melting point 710 °C (1,310 °F; 983 K) (anhydrous)
27 °C (tetrahydrate)
Boiling point 850 °C (1,560 °F; 1,120 K) (anhydrous)
52 g/100 mL (5 °C)
70 g/100 mL (70 °C)
Solubility Very slightly soluble in methanol
insoluble in ether and ethanol.
1.3660×10−2 cm3/mol
Structure
orthogonal (anhydrous)
monoclinic (monohydrate)
monoclinic (tetrahydrate)
Hazards
Safety data sheet ICSC 0290
GHS pictograms GHS08: Health hazardGHS09: Environmental hazard
GHS Signal word Warning
H373, H411
P260, P273, P314, P391, P501
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineReactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
1
1
Related compounds
Other cations
Chromium(III) sulfate
Iron(II) sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Manganese(II) sulfate usually refers to the inorganic compound with the formula MnSO4·H2O. This pale pink deliquescent solid is a commercially significant manganese(II) salt. Approximately 260,000 tonnes of manganese(II) sulfate were produced worldwide in 2005. It is the precursor to manganese metal and many other chemical compounds. Manganese-deficient soil is remediated with this salt.[1]

Structure

Coordination sphere for Mn and S in the monohydrate. The O6 coordination sphere is provided by four separate sulfate groups and a pair of mutually trans bridging aquo ligands.[2]

Like many metal sulfates, manganese sulfate forms a variety of hydrates: monohydrate, tetrahydrate, pentahydrate, and heptahydrate. All of these salts dissolve in water to give faintly pink solutions of the aquo complex [Mn(H2O)6]2+. The structure of MnSO4·H2O has been determined by X-ray crystallography (see figure). The tetrahydrate also features Mn(II) in an O6 coordination sphere provided by bridging two sulfate anions and four aquo ligands.[3]

Applications and production

Typically, manganese ores are purified by their conversion to manganese(II) sulfate. Treatment of aqueous solutions of the sulfate with sodium carbonate leads to precipitation of manganese carbonate, which can be calcined to give the oxides MnOx. In the laboratory, manganese sulfate can be made by treating manganese dioxide with sulfur dioxide:[4]

MnO2 + SO2 + H2O → MnSO4(H2O)

It can also be made by mixing potassium permanganate with sodium bisulfate and hydrogen peroxide.

Manganese sulfate is a by-product of various industrially significant oxidations that use manganese dioxide, including the manufacture of hydroquinone and anisaldehyde.[1]

Electrolysis

Electrolysis of manganese sulfate reverses the above reaction yielding manganese dioxide, which is called EMD for electrolytic manganese dioxide. Alternatively oxidation of manganese sulfate with potassium permanganate yields the so-called chemical manganese dioxide (CMD). These materials, especially EMD, are used in dry-cell batteries.[1]

Natural occurrence

Manganese(II) sulfate minerals are very rare in nature and always occur as hydrates. The monohydrate is called szmikite; the tetrahydrate is called ilesite; the pentahydrate is called jōkokuite; the hexahydrate, the most rare, is called chvaleticeite; and the heptahydrate is called mallardite.[5]

References

  1. 1.0 1.1 1.2 Reidies, Arno H.. "Ullmann's Encyclopedia of Industrial Chemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. 
  2. Wildner, M.; Giester, G. (1991). "The Crystal Structures of Kieserite-type Compounds. I. Crystal Structures of Me(II)SO4*H2O (Me = Mn, Fe, Co, Ni, Zn) (English translation)". Neues Jahrbuch für Mineralogie - Monatshefte: 296-p306. 
  3. Held, Peter; Bohatý, Ladislav (2002). "Manganese(II) Sulfate Tetrahydrate (Ilesite)". Acta Crystallographica Section E 58 (12): i121–i123. doi:10.1107/S1600536802020962. 
  4. John R. Ruhoff (1936). "n-Heptanoic acid". Organic Syntheses 16: 39. doi:10.15227/orgsyn.016.0039. 
  5. "Home". http://www.mindat.org/.