Manganese(II) sulfate

Manganese(II) sulfate

File:Manganese(II) sulfate close-up.jpg Manganese(II) sulfate monohydrate
File:Manganese(II)-sulfate-tetrahydrate-sample.jpg Manganese(II) sulfate tetrahydrate
Names
IUPAC name Manganese(II) sulfate
Identifiers
CAS Number	7785-87-7 checkY 10034-96-5 (monohydrate) checkY 10101-68-5 (tetrahydrate) checkY
3D model (JSmol)	Interactive image
ChEBI	CHEBI:86360
ChEMBL	ChEMBL1200557 ☒N
ChemSpider	22984 checkY
ECHA InfoCard
EC Number	232-089-9
E number
PubChem CID	24580
RTECS number	OP1050000 (anhydrous) OP0893500 (tetrahydrate)
UNII	IGA15S9H40 checkY W00LYS4T26 (monohydrate) checkY F46LH60L4M (tetrahydrate) checkY
CompTox Dashboard (EPA)	{{#property:P3117}}
InChI InChI=1S/Mn.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 checkY Key: SQQMAOCOWKFBNP-UHFFFAOYSA-L checkY InChI=1/Mn.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 Key: SQQMAOCOWKFBNP-NUQVWONBAV
SMILES [Mn+2].[O-]S([O-])(=O)=O
Properties
Chemical formula	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)
Solubility in water	52 g/100 mL (5 °C) 70 g/100 mL (70 °C)
Solubility	Very slightly soluble in methanol insoluble in ether and ethanol.
Magnetic susceptibility (χ)	1.3660×10−2 cm3/mol
Structure
Crystal structure	orthogonal (anhydrous) monoclinic (monohydrate) monoclinic (tetrahydrate)
Hazards
GHS labelling:
Pictograms	GHS08: Health hazardGHS09: Environmental hazard
Signal word	Warning
Hazard statements	H373, H411
Precautionary statements	P260, P273, P314, P391, P501
NFPA 704 (fire diamond)	1 0 1
Safety data sheet (SDS)	ICSC 0290
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). ☒N verify (what is checkY☒N ?) 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.

Structure

File:MnSO4(aq).png

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.

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.

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 MnO_x. In the laboratory, manganese sulfate can be made by treating manganese dioxide with sulfur dioxide:

MnO₂ + SO₂ + H₂O → MnSO₄(H₂O)

It can also be made by mixing potassium permanganate with sodium hydrogen sulfate 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.

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.

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.