Sodium permanganate
| Names | |
|---|---|
| IUPAC name
Sodium manganate(VII)
| |
| Other names
Permanganate of sodium
| |
| Properties | |
| NaMnO4 (ahydrous) NaMnO4·H2O (monohydrate) | |
| Molar mass | 141.9254 g/mol (anhydrous) 159.94 g/mol (monohydrate) |
| Appearance | Red-purple solid |
| Odor | Odorless |
| Density | 1.972 g/cm3 (monohydrate) |
| Melting point | 170 °C (338 °F; 443 K) (trihydrate) |
| Boiling point | Decomposes |
| 90 g/100 ml | |
| Solubility | Readily soluble in acetone[1] |
| Vapor pressure | ~0 mmHg |
| Hazards | |
| Safety data sheet | Spectrum (monohydrate) |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
9,000 mg/kg (rat, oral) |
| Related compounds | |
| Related compounds
|
Ammonium permanganate Potassium permanganate Barium permangnate |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Sodium permanganate is a chemical compound with the formula NaMnO4, more commonly encountered as monohydrate. It is closely related to the more common potassium permanganate, though it's not as often encountered.
Contents
Properties
Chemical
Sodium permanganate is a strong oxidizer.
Addition of conc. sulfuric acid will yield manganese heptoxide.
Physical
Sodium permangate is a red or purplish solid, extremely soluble in water.
Availability
Sodium permangante is sometimes sold by chemical suppliers, though it's less available than its potassium counterpart.
In many countries the sale of permanganates is regulated and sodium permanganate is no exception.
Preparation
Sodium permanganate can be easily prepared by reacting a mixture of sodium hypochlorite and sodium hydroxide, with freshly prepared manganese dioxide.
- 2 MnO2 + 3 NaOCl + 2 NaOH → 2 NaMnO4 + 3 NaCl + H2O
While easy to do, this reaction will only give small amounts of sodium permanganate, as during the process most of the hypochlorite decomposes.
Electrolysis of a solution of 5-20% NaOH using manganese metal will give sodium permanganate.[2] Sodium carbonate can also be used.[3]
The substitution reaction between sodium sulfate and calcium or barium permanganate will also give sodium permanganate. This route is attractive due to the very high solubility of sodium permanganate. However, due to the poor solubility of the precursors, this process may take a while.
A less known route involves the addition of calcium hypochlorite and sodium hydroxide to a concentrated solution of manganese(II) chloride. The resulting product is heated on a steam bath, then purified. The resulting sodium permanganate solution is determined to be fairly concentrated. While it was believed that the permanganate from this route was obtained from the chlorate derived from the decomposition of the hypochlorite during heating, a repeat of this method using potassium chlorate gave no permanganate.[4]
Sodium permanganate cannot be prepared analogously to the route to KMnO4 because the required intermediate manganate salt, Na2MnO4, is unstable and does not form.
Projects
- Oxidizer
- Make manganese heptoxide
Handling
Safety
Sodium permangante is a strong oxidizer and should be handled with proper protection.[5]
Storage
Should be kept in airtight containers.
Disposal
Can be neutralized with hydrogen peroxide, resulting sodium hydroxide and manganese dioxide. The latter can be recycled through sedimentation or filtration.
References
- ↑ Grimm, H. G.; Peters, C.; Wolff, H.; Zeitschrift fuer Anorganische und Allgemeine Chemie; vol. 236; (1938); p. 57 - 77
- ↑ Zaretskii, S. A.; Zharnitskii, I. G.; Bogdanova, I. A.; Soviet Electrochem. Proc. 4th Conf. Electrochem., Moscow 1956 (1959), New York 1961, Bd. III, pp. 110/3
- ↑ Agladze, R. I.; Domanskaya, G. M.; Zhurnal Prikladnoi Khimii (Sankt-Peterburg, Russian Federation); vol. 24; (1951);
- ↑ Baxter, G. P.; Frevert; American Chemical Journal; vol. 34; (1905); p. 114 - 114
- ↑ https://cameochemicals.noaa.gov/chemical/1515
