Potassium permanganate decomposition

Filling the Gas Meter with Oxygen. Measure the volume of the meter. Write the equation of potassium permanganate decomposition. Calculate how many grammes of the salt have to be taken for the evolved oxygen to fill the gas meter up to two-thirds of its volume. 

The overall decomposition of solid potassium permanganate ia the temperature range of 250—300°C leads to the formation of a delta-manganese dioxide (shown ia brackets) and can be represented as follows ... 

The kinetics of the reaction are relatively slow and permanganate solutions exhibit greatest stabiUty around a neutral pH. The decomposition rates increase below pH 3 or above pH 10. Potassium permanganate solutions are stable at elevated temperatures, up to approximately 3 N sodium hydroxide, above which decomposition into manganate occurs. 

The potassium permanganate crystals are dried at atmospheric pressure below 150°C, cooled, and packaged. Care is taken to prevent heating the product above 200°C during drying to avoid autocatalytic exothermic decomposition of the product. 

It states that the rate is proportional to the fraction x that has decomposed (which is dominant early in the reaction) and to the fraction not decomposed (which is dominant in latter stages of reaction). The decomposition of potassium permanganate and some other solids is in accordance with this equation. The shape of the plot of x against t is sigmoid in many cases, with slow reactions at the oeginning and end, but no theory has been proposed that explains everything. 

This is known as the Prout—Tompkins equation and has found application to many systems, in addition to the thermal decomposition of potassium permanganate [465] with which it is often associated. The kinetic behaviour of silver permanganate was somewhat different and in a variation of... 

Reference has already been made to the dehydration of alums (Sect. 1.2 and Table 10), decomposition of ammonium metal phosphates (Sect. 4.1.5) and the use of KMn04—KCIO4 solid solutions in mechanistic studies of the decomposition of potassium permanganate (Sect. 3.6). 

The S=N bond in sulphilimines is relatively sensitive to hydrolysis and so the oxidation of these compounds to sulphoximines must be carried out under mild conditions. For example, attempted oxidation of many sulphilimines with potassium permanganate usually leads to decomposition without formation of the required product17S. It should be noted, however, that once the sulphoximine is formed the S=N bond is much more stable and hence less readily available for reaction. 

In a review of the course and mechanism of the catalytic decomposition of ammonium perchlorate, the considerable effects of metal oxides in reducing the explosion temperature of the salt are described [1], Solymosi s previous work had shown reductions from 440° to about 270° by dichromium trioxide, to 260° by 10 mol% of cadmium oxide and to 200°C by 0.2% of zinc oxide. The effect of various concentrations of copper chromite , copper oxide, iron oxide and potassium permanganate on the catalysed combustion of the propellant salt was studied [2], Similar studies on the effects of compounds of 11 metals and potassium dichromate in particular, have been reported [3], Presence of calcium carbonate or calcium oxide has a stabilising effect on the salt, either alone or in admixture with polystyrene [4],... 

The medium impact-sensitivity of this solid propellant component is greatly increased by co-crystallisation of certain impurities, notably nitryl perchlorate, potassium periodate and potassium permanganate [1]. The presence of certain minimum amounts of mono-, di, tri- or tetra-methylammonium perchlorates in the salt leads to a single step decomposition, at around 290°C for the monoderivative [2],... 

A mixture of 0.5% of potassium permanganate with an ammonium nitrate explosive caused an explosion 7 h later. This was owing to formation and exothermic decomposition of ammonium permanganate, leading to ignition. 

An unstable powerful oxidant, it explodes between 40 and 70°C, or on friction or impact, sensitivity being as great as that of mercury fulminate [1], Detonation occurs at 95°C, and under vacuum explosive decomposition occurs above 10°C [2], See Potassium permanganate Sulfuric acid... 

Potassium pentafluoroaluminate monohydrate, 2 371 Potassium perbromate, 4 335 Potassium perchlorate, 18 277 Potassium permanganate, 9 635-636 crystallographic studies on, 15 601 as a detoxicant, 15 621 decomposition of, 15 597 as an ignitable waste, 15 615 industrial-scale production of, 15 606 manufacture of, 15 601-606 for purifying carbon dioxide streams, 4 815... 

The oxidation of alkenes with potassium permanganate in the presence of chiral menthylammonium salts has been reported to produce chiral 1,2-diols with low optical purity. It is possible that the products are contaminated with the catalysts or their decomposition products, as no asymmetric induction was observed with (+)-l-phenylethylammonium salts [30]. 

Decomposition was initiated by the addition of a concentrated aqueous solution of calcium and sodium permanganate to the hydrogen peroxide. The use of potassium permanganate proved ineffective since KMn04 is insufficiently soluble in water and the solution contains inadequate MnO -ions for rapid initiation of the reaction. 

Oxidative decomposition of 2//-pyrantetracarboxylic acid 149 with hydrogen peroxide or nitric acid gave traces of succinic and oxalic acids, respectively.194 3-Methyl-4//-thiopyran (3) was reported to be oxidized with potassium permanganate to oxalic and acetic acids.6... 

Hydrogen trisulphide is much more easily combustible than the crude parent hydrogen polysulphide. Exposure to light tends to accelerate its decomposition. It slowly reduces concentrated sulphuric acid to sulphur dioxide, whilst on contact with dry silver oxide, cupric oxide, lead dioxide or mercuric oxide, it bursts into explosive combustion,2 a residue of the metallic sulphide being obtained. Many other metallic oxides and most salts bring about a less vigorous decomposition metals in the massive condition only react with it slowly. With potassium permanganate or dichromate the reaction is violent. 

Phenyl -tolyl selenide in aqueous suspension is boiled with potassium permanganate for several hours. The manganese mud is dissolved and the 4-carboxydiphenyl selenoxide precipitated by passing in sulphur dioxide. After filtration the precipitate is macerated with dilute sodium carbonate solution, the products of oxidation being separated in this manner into phenyl p-tolyl selenoxide and 4-carboxydiphenyl selenoxide. Addition of dilute sulphuric acid to the sodium carbonate extract causes the separation of 4-carboxydiphenyl selenoxide, which is crystallised from alcohol. The product is a microcrystalline powder, melting with decomposition at 253° to 255° C. Attempts to resolve it into optically active forms have failed the l-menthylamine salt melts at 220° to 222° C. with decomposition, and the d-a-phenyl-ethylamine salt forms feathery needles, M.pt. 194° to 195° C. with decomposition.3... 

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