Sodium permanganate

Sodium permanganate

Names
IUPAC name Sodium manganate(VII)
Other names Sodium permanganate, permanganate of sodium
Identifiers
CAS Number	(monohydrate) 10101-50-5 (monohydrate) N
ChemSpider	23303 Y
Jmol 3D model	Interactive image
PubChem	23673458
RTECS number	SD6650000
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
SMILES [Na+].[O-][Mn](=O)(=O)=O
Properties
Chemical 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 (97 °F; 309 K) (170 °C for trihydrate)
Solubility in water	90 g/100 mL
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
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 to produce. It is mainly available as the monohydrate. This salt 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.

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. It is gaining popularity in water treatment for taste, odor, and zebra mussel control.