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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. Potassium permanganate is widely used in the chemical industry and laboratories as a strong oxidizing agent , and also as a medication for dermatitis , for cleaning wounds , and general disinfection .
This reaction illustrates the relatively rare role of hydroxide as a reducing agent. The concentration of K 2 MnO 4 in such solutions can be checked by measuring their absorbance at 610 nm. The one-electron reduction of permanganate to manganate can also be effected using iodide as the reducing agent: 2 KMnO 4 + 2 KI → 2 K 2 MnO 4 + I 2
The white smoke-like vapor produced by the reaction is a mixture of carbon dioxide gas and water vapor. Since the reaction is highly exothermic, initial sparking occurs, followed by a lilac- or pink-colored flame. [9] When energy or heat is added to electrons, their energy level increases to an excited state.
A permanganate (/ p ər ˈ m æ ŋ ɡ ə n eɪ t, p ɜːr-/) [1] is a chemical compound with the manganate(VII) ion, MnO − 4, the conjugate base of permanganic acid.Because the manganese atom has a +7 oxidation state, the permanganate(VII) ion is a strong oxidising agent.
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.
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]
Water-reactive substances [1] are those that spontaneously undergo a chemical reaction with water, often noted as generating flammable gas. [2] Some are highly reducing in nature. [ 3 ] Notable examples include alkali metals , lithium through caesium , and alkaline earth metals , magnesium through barium .
Sodium permanganate is the inorganic compound with the formula Na MnO 4.It is closely related to the more commonly encountered potassium permanganate, but it is generally less desirable, because it is more expensive to produce.