Manganese(II)-potassium sulfate

Manganese(II)-potassium sulfate
Names:	manganese(II)-potassium sulfate manganese-potassium sulfate
Formula:	K2Mn(SO4)2 (anhydrous) K2Mn(SO4)2 · 2H2O (dihydrate) K2Mn(SO4)2 · 4H2O (tetrahydrate)
Molar mass:	325.256 g/mol (anhydrous) 361.286 g/mol (dihydrate) 397.316 g/mol (tetrahydrate)
Crystal system:	monoclinic (tetrahydrate) a=12.03 Å, b=9.61 Å, c=9.98 Åα=90°, β=95°, γ=90° triclinic (dihydrate) a=6.574 Å, b=7.332 Å, c=10.7 Åα=72.89°, β=73.91°, γ=69.77°
Shapes:	https://en.crystalls.info/w/uploads/media/9/9a/Truncated_deformed_hexagonal_prism.json Truncated deformed hexagonal prism https://en.crystalls.info/w/uploads/media/d/d0/Truncated_deformed_oblique_hexagonal_prism.json Truncated deformed oblique hexagonal prism https://en.crystalls.info/w/uploads/media/f/fd/Beveled_truncated_rhombic_prism.json Beveled truncated rhombic prism
Color:	pink pale pink
Stability:	erodes (tetrahydrate)

Description

Inorganic compound, double salt of transitional metal manganese, alkaline metal potassium and inorganic sulfuric acid. From water solutions crystallizes as tetrahydrate and dihydrate.

Precursors

Reaction between manganese(II) and potassium sulfates

Chemical equation:

K₂SO₄ + MnSO₄ = K₂Mn(SO₄)₂↓

For preparation of 100.00g of manganese(II)-potassium sulfate tetrahydrate

tetrahydrate

dihydrate

anhydrous

а 60.68g of manganese(II) sulfate pentahydrate

pentahydrate

tetrahydrate

monohydrate

anhydrous

and 43.86g of potassium sulfate is required.

Dissolve compounds in hot water apart and then mix solutions into one container with intense stirring. Cooling or evaporation of a solution will cause double salt crystallyzation.

Due to the high solubility of the product and the heat generated during dissolution, compounds should be added carefully and less amount of water is recommended..

Influence of impurities

Excess of one of sulfates leads to changing a shape of the final crystal. Excess of potassium sulfate makes crystals cloudy/opaque.

Influence of pH level

Addition of surfactants has a positive influence on crystal shape and transparency. For example, addition of soap containing sodium lauryl sulfate makes crystal transparent and sharp-edged. Same effect can be achieved by addition of baking soda (~1g of per 100g of solution) - a precipitate containing impurities is formed (e.g. iron salts), solution should be left intact for a while, and then filtered.

Notes

Unlike manganese(II)-ammonium sulfate, potassium salt produces crystals of tetrahydrate instead of hexahydrate, and thus have a different shape.

Storage conditions

For crystal storing use hermetic vessel with wadding moistened with such solution near the crystal. You can use such alternatives as vessel with vaseline or vegetable oil, organic non-hygroscopic solvent (kerosene or liquid paraffin). Also you can use acrylate polymer or another kinds of solidifying plastic.

Solubility

TableGraph

Temperature	g/100,00 g water
25°C298.15 K <br />77 °F <br />536.67 °R <br />	~60

Gallery

• 

  Manganese(II)-potassium sulfateManzana cristal, redditManzana cristalReddit

• 

  Manganese(II)-potassium sulfateMartinov Maxim, VKontakteMartinov MaximVKontakte

• 

  Manganese(II)-potassium sulfateMartinov Maxim, VKontakteMartinov MaximVKontakte

• 

  Manganese(II)-potassium sulfateMaxim Martinov, VKontakteMaxim MartinovVKontakte

• 

  Manganese(II)-potassium sulfateMartinov Maxim, VKontakteMartinov MaximVKontakte

• 

  Manganese(II)-potassium sulfateMartinov Maxim, VKontakteMartinov MaximVKontakte

Sources

• Michel Fleck , U. Kolitsch , B. Hertweck , G. Giester , M. Wildner , M. Prem, A. Wohlschläger, Crystal structures of the double salt dihydrates K2Cd(SeO4)2·2H2O, K2Mn(SO4)2·2H2O, (NH4)2Cu(SeO4)2·2H2O and KFeH(SO4)2·2H2O
• W. Schneider, Redefining the crystals structure of Mangenese-Leonite, K2Mn(SO4)2.4H2O

Navigation

Potassium compounds
Salts	Potassium bromate (KBrO3) • Potassium bromide (KBr) • Potassium chlorate (KClO3) • Potassium chloride (KCl) • Potassium chromate (K2CrO4) • Potassium dihydrophosphate (KH2PO4) • Potassium dichromate (K2Cr2O7) • Potassium iodide (KI) • Potassium hydrofluoride (KHF2) • Potassium hydrophosphate (K2HPO4) • Potassium hydrophthalate (KC8H6O4) • Potassium metavanadate (KVO3) • Potassium nitrate (KNO3) • Potassium sulfate (K2SO4) • Potassium thiocyanate (KNCS)
Double salts	Aluminum-potassium sulfate (KAl(SO4)2) • Antimony(III)-potassium tartrate (K2Sb2(C4H2O6)2) • Chromium(III)-potassium sulfate (KCr(SO4)2) • Cobalt(II)-potassium sulfate (K2Co(SO4)2) • Copper(II)-potassium sulfate (K2Cu(SO4)2) • Indium(III)-potassium sulfate (KIn(SO4)2) • Iron(II)-potassium sulfate (K2Fe(SO4)2) • Iron(III)-potassium sulfate (KFe(SO4)2) • Lithium-potassium sulfate (KLiSO4) • Magnesium-potassium sulfate (K2Mg(SO4)2) • Magnesium-potassium sulfate-chromate (K2CrO4 · MgSO4) • Manganese(II)-potassium sulfate (K2Mn(SO4)2) • Nickel-potassium sulfate (K2Ni(SO4)2) • Potassium-sodium tartrate (KNaC4H4O6) • Vanadium(III)-ammonium sulfate (NH4V(SO4)2) • Zinc-potassium sulfate (K2Zn(SO4)2)
Complexes	Potassium dioxalatocuprate(II) (K2[Cu(C2O4)2]) • Potassium hexanitrocobaltate(III) (K3[Co(NO2)6]) • Potassium hexachlororhodiate(III) (K3[RhCl6]) • Potassium hexacyanocobaltate(III) (K3[Co(CN)6]) • Potassium hexacyanoferrate(II) (K4[Fe(CN)6]) • Tripotassium-sodium hexacyanoferrate(II) (K3Na[Fe(CN)6]) • Potassium hexacyanoferrate(III) (K3[Fe(CN)6]) • Potassium hexacyanochromate(III) (K3[Co(CN)6]) • Potassium tetraiodobismuthate (К[BiI4]) • Potassium tetraiodomercurate(II) (K2[HgI4]) • Potassium trioxalatoaluminate (K3[Al(C2O4)3]) • Potassium trioxalatocobaltate(III) (K3[Co(C2O4)3]) Potassium trioxalatoferrate(III) (K3[Fe(C2O4)3]) • Potassium-sodium trioxalatoferrate(III) (K5Na[Fe(C2O4)3]2) • Dipotassium-sodium trioxalatoferrate(III) (K2Na[Fe(C2O4)3]) • Potassium trioxalatochromate(III) (K3[Cr(C2O4)3])