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Potassium permanganate is an inorganic compound with the chemical formula KMnO 4.It is a purplish-black crystalline salt, which dissolves in water as K + and MnO − 4 ions to give an intensely pink to purple solution.
For instance, potassium permanganate decomposes at 230 °C to potassium manganate and manganese dioxide, releasing oxygen gas: 2 KMnO 4 → K 2 MnO 4 + MnO 2 + O 2 A permanganate can oxidize an amine to a nitro compound , [ 7 ] [ 8 ] an alcohol to a ketone , [ 9 ] an aldehyde to a carboxylic acid , [ 10 ] [ 11 ] a terminal alkene to a ...
Potassium permanganate will decompose into potassium manganate, manganese dioxide and oxygen gas: 2 KMnO 4 → K 2 MnO 4 + MnO 2 + O 2. This reaction is a laboratory method to prepare oxygen, but produces samples of potassium manganate contaminated with MnO 2. The former is soluble and the latter is not.
The chemical chameleon reaction shows the process in reverse, by reducing violet potassium permanganate first to green potassium manganate and eventually to brown manganese dioxide: [1] [2] [5] KMnO 4 (violet) → K 2 MnO 4 (green) → MnO 2 (brown/yellow suspension) Blue potassium hypomanganate may also form as an intermediate. [6]
The biggest difference between the two chemicals is that potassium permanganate is less soluble than sodium permanganate. [5] Potassium permanganate is a crystalline solid that is typically dissolved in water before application to the contaminated site. [3] Unfortunately, the solubility of potassium permanganate is dependent on temperature.
Crystalline potassium permanganate (KMnO 4) is placed in an evaporating dish. A depression is made at the center of the permanganate powder and glycerol liquid is added to it. The white smoke-like vapor produced by the reaction is a mixture of carbon dioxide gas and water vapor.
The contaminants are determined to be mostly ash and water. Toxic gases such as dinitrogen tetraoxide and nitrogen dioxide are evolved in the process. The final product is typically 47.06% carbon, 27.97% oxygen, 22.99% water, and 1.98% ash with a carbon-to-oxygen ratio of 2.25. All of these results are comparable to the methods that preceded them.
Ammonium permanganate decomposes explosively to manganese dioxide, nitrogen, and water: [2] 2 NH 4 MnO 4 → 2 MnO 2 + N 2 + 4 H 2 O. Ammonium permanganate decomposes slowly in storage even at normal temperatures. A sample stored for 3 months was only 96% pure, after 6 months it assumed color of iodine and had strong smell of nitrogen oxides.