Sodium permanganate

Sodium permanganate
IUPAC name Sodium manganate(VII)
Other names Sodium permanganate, permanganate of sodium
Identifiers
CAS number	10101-50-5 Y
PubChem	24929
ChemSpider	23303 Y
RTECS number	SD6650000
Jmol-3D images	Image 1
SMILES [Na+].[O-][Mn](=O)(=O)=O
InChI InChI=1S/Mn.Na.4O/q;+1;;;;-1 Y Key: WPWYHBSOACXYBB-UHFFFAOYSA-N Y InChI=1/Mn.Na.4O/q;+1;;;;-1/rMnO4.Na/c2-1(3,4)5;/q-1;+1 Key: WPWYHBSOACXYBB-NJUWVQTAAZ
Properties
Molecular formula	NaMnO4
Molar mass	141.9254 g/mol 159.94 g/mol (monohydrate)
Appearance	Red solid
Density	1.972 g/cm3 (monohydrate)
Melting point	36 °C
Boiling point	100 °C
Solubility in water	900 g/L
Hazards
Main hazards	Oxidizer
Y permanganate (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

Sodium permanganate is the inorganic compound with the formula NaMnO₄. It is closely related to the more commonly encountered potassium permanganate, but it is generally less desirable, because it is more expensive, absorbs water from the atmosphere, and has a low melting point. Being about 15 times more soluble than KMnO₄, sodium permanganate finds some applications where very high concentrations of MnO₄^- are sought.

Preparation and properties

See also: Potassium permanganate

Sodium permanganate cannot be prepared analogously to the route to KMnO₄ because the required intermediate manganate salt, Na₂MnO₄, does not form. Thus less direct routes are used including conversion from KMnO₄.^[1]

Sodium permanganate behaves similarly to potassium permanganate. It dissolves readily in water to give deep purple solutions, evaporation of which gives prismatic purple-black glistening crystals of the monohydrate NaMnO₄·H₂O. The potassium salt does not form a hydrate. Because of its hygroscopic nature, it is less useful in analytical chemistry than its potassium counterpart.

It can be prepared by the reaction of manganese dioxide with sodium hypochlorite:

2 MnO₂ + 3 NaClO + 2 NaOH → 2 NaMnO₄ + 3 NaCl + H₂O

Applications

Because of its high solubility, its aqueous solutions are used as etchants in printed circuitry.^[1]

References

1. ^ ^{a b} Arno H. Reidies "Manganese Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_123