Barium permanganate is a chemical compound, with the formula Ba(MnO4)2.PubChem It forms violet to brown crystals that are soluble in water.
Preparation Barium permanganate may be produced by disproportionation of barium manganate in a mildly acidic solution, including solutions carbon dioxide or sulfuric acid:
3 BaMnO4 + 2 CO2 → Ba(MnO4)2 + 2 BaCO3 + MnO2 3 BaMnO4 + 2 H2SO4 → Ba(MnO4)2 + 2 BaSO4 + MnO2 + 2 H2O It can also be prepared by oxidation of barium manganate with strong oxidants. Preparations relying on aqueous reactions of barium manganate are extremely slow process due to the low solubility of the manganate.
Another way to synthesize barium permanganate is by the reaction between silver permanganate and barium chloride. Highly pure samples can be obtained from the similar reaction between potassium permanganate and aluminium sulfate to form aluminium permanganate, which is then reacted with a stoichiometric amount of barium hydroxide.
Reactions Barium permanganate is a strong oxidizer. It is thermally stable up to . Above this temperature it decomposes in two stages, between and .
The decomposition has been shown to proceed at slow rates above , and that irradiation with UV or X-rays lowers this temperature. Crystal defects and impurities play a role in the mechanism.
Permanganic acid can be prepared by the reaction of dilute sulfuric acid with a solution barium permanganate, the insoluble barium sulfate byproduct being removed by filtering:
The sulfuric acid used must be dilute; reactions of permanganates with concentrated sulfuric acid yield the anhydride, manganese heptoxide.
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