Search results
Results from the WOW.Com Content Network
The reagent is an alkaline solution of potassium permanganate. Reaction with double or triple bonds (R 2 C=CR 2 or R−C≡C−R) causes the color to fade from purplish-pink to brown. Aldehydes and formic acid (and formates) also give a positive test. [43] The test is antiquated. Baeyer's reagent reaction
The exothermic (heat producing) reaction between potassium permanganate (KMnO 4), a strong oxidizing agent, and glycerol (C 3 H 5 (OH) 3), a readily oxidised organic substance, is an example of an experiment sometimes referred to as a "chemical volcano". [7] [8]
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.
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.
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 basic chemical reaction involved in the Hummers' method is the oxidation of graphite, introducing molecules of oxygen to the pure carbon graphene. The reaction occurs between the graphene and the concentrated sulfuric acid with the potassium permanganate and sodium nitrate acting as catalysts.
Permanganic acid has also been prepared through the reaction of hydrofluorosilicic acid with potassium permanganate, [4] through electrolysis, and through hydrolysis of manganese heptoxide, though the last route often results in explosions. [5] Crystalline permanganic acid has been prepared at low temperatures as the dihydrate, HMnO 4 ·2H 2 O. [3]
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.