Manganese(II) sulfate

Manganese(II) sulfate
Manganese(II) sulfate monohydrate
Manganese(II) sulfate tetrahydrate
IUPAC name Manganese(II) sulfate
Identifiers
CAS number	7785-87-7 Y,  10034-96-5 (monohydrate) 10101-68-5 (tetrahydrate)
PubChem	24580
ChemSpider	22984 Y
UNII	IGA15S9H40 Y
EC number	232-089-9
ChEMBL	CHEMBL1200557 N
RTECS number	OP1050000 (anhydrous) OP0893500 (tetrahydrate)
Jmol-3D images	Image 1
SMILES [Mn+2].[O-]S([O-])(=O)=O
InChI InChI=1S/Mn.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 Y Key: SQQMAOCOWKFBNP-UHFFFAOYSA-L Y InChI=1/Mn.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 Key: SQQMAOCOWKFBNP-NUQVWONBAV
Properties
Molecular formula	MnSO4
Molar mass	151.001 g/mol (anhydrous) 169.02 g/mol (monohydrate) 223.07 g/mol (tetrahydrate)
Appearance	pale pink crystalline solid (tetrahydrate)
Density	3.25 g/cm 3 (anhydrous) 2.95 g/cm3 (monohydrate) 2.107 g/cm3 (tetrahydrate)
Melting point	710 °C (anhydrous) 27 °C (tetrahydrate)
Boiling point	850 °C (anhydrous)
Solubility in water	393 g/L (24 °C) 262 g/L (100 °C)
Structure
Crystal structure	orthogonal (anhydrous) monoclinic (monohydrate) monoclinic (tetrahydrate)
Hazards
MSDS	ICSC 0290
EU Index	025-003-00-4
EU classification	Harmful (Xn) Dangerous for the environment (N)
R-phrases	R48/20/22, R51/53
S-phrases	(S2), S22, S61
NFPA 704	0 1 1
Related compounds
Other cations	Chromium(III) sulfate Iron(II) sulfate
N sulfate (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

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 thousand tonnes of manganese(II) sulfate were produced worldwide in 2005.^[1] It is the precursor to manganese metal and many other chemical compounds. Mn-deficient soil is remediated with this salt.

Structure

Like many metal sulfates, manganese sulfate forms a variety of hydrates: monohydrate, tetrahydrate, pentahydrate, and heptahydrate. The monohydrate is most common. All of these salts dissolve to give faintly pink solutions of the aquo complex [Mn(H₂O)₆]²⁺. The pale pink colour of Mn(II) salts is highly characteristic.

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:^[2]

MnO₂ + SO₂ → MnSO₄

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

Electrolysis of manganese sulfate yields 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]

References

1. ^ ^{a b c} Arno H. Reidies "Manganese Compounds" Ullmann's Encyclopedia of Chemical Technology 2007; Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_123
2. ^ John R. Ruhoff (1943), "n-Heptanoic acid", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2p0315 ; Coll. Vol. 2: 315