Manganese(II) carbonate

Manganese carbonate is a compound with the chemical formula MnCO3. Manganese carbonate occurs naturally as the mineral rhodochrosite but it is typically produced industrially. It is a pale pink, water-insoluble solid. Approximately 20,000 metric tonnes were produced in 2005.[3]

Manganese(II) carbonate
Calcium-carbonate-xtal-3D-SF
Manganese (II) Carbonate
Names
IUPAC name
Manganese(II) carbonate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.009.040
EC Number
  • 209-942-9
UNII
Properties
MnCO3
Appearance White to faint pink solid
Density 3.12 g/cm3
Melting point 200–300 °C (392–572 °F; 473–573 K)
decomposes[1][2]
negligible
2.24 x 10−11
Solubility soluble in dilute acid, CO2
insoluble in alcohol, ammonia
+11,400·10−6 cm3/mol
1.597 (20 °C, 589 nm)
Structure
hexagonal-rhombohedral
Thermochemistry
94.8 J/mol·K[2]
109.5 J/mol·K[2]
-881.7 kJ/mol[2]
-811.4 kJ/mol[2]
Hazards
Flash point Non-flammable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Structure and production

MnCO3 adopts a structure like calcite, consisting of manganese(II) ions in an octahedral coordination geometry.[4]

Treatment of aqueous solutions of manganese(II) nitrate with ammonia and carbon dioxide leads to precipitation of this faintly pink solid. The side product, ammonium nitrate is used as fertilizer.

Rhodochrosite-Pyrite-Calcite-219228
Pink rhodochrosite, the mineral form of MnCO3, is of practical value as well as sought by collectors.

Reactions and uses

The carbonate is insoluble in water but, like most carbonates, hydrolyses upon treatment with acids to give water-soluble salts.

Manganese carbonate decomposes with release of carbon dioxide, i.e. calcining, at 200 °C to give MnO1.88:

MnCO3 + 0.44 O2 → MnO1.8 + CO2

This method is sometimes employed in the production of manganese dioxide, which is used in dry-cell batteries and for ferrites.[3]

Manganese carbonate is widely used as an additive to plant fertilizers to cure manganese deficient crops. It is also used in health foods, in ceramics as a glaze colorant and flux, and in concrete stains.[5]

It is used in medicine as a hematinic.

Toxicity

Manganese poisoning, also known as manganism, may be caused by long-term exposure to manganese dust or fumes.

See also

References

  1. ^ Sigma-Aldrich Co., Manganese(II) carbonate. Retrieved on 2014-05-06.
  2. ^ a b c d e http://chemister.ru/Database/properties-en.php?dbid=1&id=3854
  3. ^ a b Arno H. Reidies (2007). "Manganese Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_123.
  4. ^ Pertlik, F. (1986). "Structures of hydrothermally synthesized cobalt(II) carbonate and nickel(II) carbonate". Acta Crystallographica Section C. 42: 4–5. doi:10.1107/S0108270186097524.
  5. ^ "How To Stain Concrete with Manganese"
Carbonates
H2CO3 He
Li2CO3,
LiHCO3
BeCO3 B C (NH4)2CO3,
NH4HCO3
O F Ne
Na2CO3,
NaHCO3,
Na3H(CO3)2
MgCO3,
Mg(HCO3)2
Al2(CO3)3 Si P S Cl Ar
K2CO3,
KHCO3
CaCO3,
Ca(HCO3)2
Sc Ti V Cr MnCO3 FeCO3 CoCO3 NiCO3 CuCO3 ZnCO3 Ga Ge As Se Br Kr
Rb2CO3 SrCO3 Y Zr Nb Mo Tc Ru Rh Pd Ag2CO3 CdCO3 In Sn Sb Te I Xe
Cs2CO3,
CsHCO3
BaCO3   Hf Ta W Re Os Ir Pt Au Hg Tl2CO3 PbCO3 (BiO)2CO3 Po At Rn
Fr Ra   Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
La2(CO3)3 Ce2(CO3)3 Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Ac Th Pa UO2CO3 Np Pu Am Cm Bk Cf Es Fm Md No Lr
Chalybeate

Chalybeate () waters, also known as ferruginous waters, are mineral spring waters containing salts of iron.

Glossary of chemical formulas

This is a list of common chemical compounds with chemical formulas and CAS numbers, indexed by formula. This complements alternative listing at inorganic compounds by element. There is no complete list of chemical compounds since by nature the list would be infinite.

Note: There are elements for which spellings may differ, such as aluminum/ aluminium, sulfur/ sulphur, and caesium/ cesium.

List of CAS numbers by chemical compound

This is a list of CAS numbers by chemical formulas and chemical compounds, indexed by formula. This complements alternative listings to be found at list of inorganic compounds, list of organic compounds and inorganic compounds by element.

Manganese

Manganese is a chemical element with the symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a transition metal with important industrial alloy uses, particularly in stainless steels.

Historically, manganese is named for pyrolusite and other black minerals from the region of Magnesia in Greece, which also gave its name to magnesium and the iron ore magnetite. By the mid-18th century, Swedish-German chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite (now known to be manganese dioxide) contained a new element, but they were unable to isolate it. Johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon.

Manganese phosphating is used for rust and corrosion prevention on steel. Ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers. Manganese dioxide is used as the cathode (electron acceptor) material in zinc-carbon and alkaline batteries.

In biology, manganese(II) ions function as cofactors for a large variety of enzymes with many functions. Manganese enzymes are particularly essential in detoxification of superoxide free radicals in organisms that must deal with elemental oxygen. Manganese also functions in the oxygen-evolving complex of photosynthetic plants. While the element is a required trace mineral for all known living organisms, it also acts as a neurotoxin in larger amounts. Especially through inhalation, it can cause manganism, a condition in mammals leading to neurological damage that is sometimes irreversible.

Manganese(II) acetate

Manganese(II) acetate are chemical compounds with the formula Mn(CH3CO2)2.(H2O)n where n = 0, 2, 4.. It is used as a catalyst and as fertilizer.

Manganese(II) chloride

Manganese(II) chloride describes a series of compounds with the formula MnCl2(H2O)x, where the value of x can be 0, 2, or 4. The tetrahydrate is the most common form of "manganese(II) chloride" and is the tetrahydrate with the formula MnCl2·4H2O. The anhydrous form and a dihydrate MnCl2·2H2O are also known. Like many Mn(II) species, these salts are pink, with the paleness of the color being characteristic of transition metal complexes with high spin d5 configurations.

Solubility table

The table below provides information on the variation of solubility of different substances (mostly inorganic compounds) in water with temperature, at 1 atmosphere pressure. Units of solubility are given in grams per 100 millilitres of water (g/100 ml), unless shown otherwise. The substances are listed in alphabetical order.

Manganese compounds

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