Potassium chlorate melting point

The decomposition of potassium chlorate(V) is catalysed by manganese(IV) oxide, Mn02, and oxygen is evolved on heating the mixture below the melting point of the chlorate(V). 

Potassium chlorate, KCIO3, is a colorless, crystalline material with a melting point of 640 K. Just above the melting-point temperature, it decomposes to produce oxygen molecules according to ... 

Potassium chlorate decomposes on heating below its melting point and in the presence of a catalyst, forming potassium chloride and oxygen. The reaction is catalyzed by manganese dioxide and is used in laboratory preparation of oxygen ... 

Several factors contribute to the instability of potassium chlorate-containing compositions. The first is the low (356°C) melting point and low decomposition temperature of the oxidizer. Soon after melting, KCIO 3 decomposes according to equation 3.1. 

Mixtures containing barium nitrate as the sole oxidizer are typically characterized by high ignition temperatures, relative to potassium nitrate and potassium chlorate compositions. The higher melting point of barium nitrate is responsible for these higher ignition values. 

FIG. 5.5 Thermogram of pure potassium chlorate, KCIO thermal events are observed prior to the melting point (356°Q. Exothermic decomposition occurs above the melting point as oxygen gas is liberated. 

FIG. 5.6 The potassium chlorate/sulfur system. Sulfur endo-therms are seen near 105° and 119°C, as expected. A violent exothermic reaction is observed below 150 C. The ignition temperature is approximately 200 degrees below the melting point of the oxidi2er (KCIO3 m.p. = 356°C). Ignition occurs near the temperature at which S 3 molecules fragment into smaller units. 

Potassium chlorate forms colorless to white crystals, white granules or powder. The crystals have a melting point of 368 Celsius, and are relatively insoluble in water and most organic solvents. However, the crystals are soluble in boiling water. Potassium chlorate forms explosives mixtures with combustible materials. These mixtures readily ignite from friction, heat, flames, or sparks. Potassium chlorate should be kept away from iodides and tartaric acid. 

Potassium chlorate forms monoclinic crystals,8 its melting-point being given as 357 10° C.,9 370° C.,10 and 372° C.11 When a solution obtained by treatment of crude Californian petroleum with concentrated sulphuric acid and dilution with water is added to a solution in water of the ordinary tabular potassium chlorate, and the mixture con-... 

Bromine attacks it at red heat with incandescence chlorine is less vigorous in its action, whilst iodine and hydrogen iodide have no action, even at 1100° C. The chlorate and nitrate of potassium do not affect it at their melting-points, but at higher temperatures decompose it with incandescence. Fused alkali hydroxides and carbonates decompose it rapidly. Concentrated sulphuric acid is without action in the cold, but with the boiling acid ferrous sulphate is produced. Dilute nitric acid dissolves it when hot, and the concentrated acid acts vigorously. Dilute hydrochloric acid is without action, and the hot concentrated acid acts only slowly. 

Example 4. When potassium chlorate, KClOg, is carefully heated (at a temperature just above its melting point, and lower than that at which oxygen is evolved rapidly in the absence of a catalyst), potassium perchlorate, KCIO, is formed, together with potassium chloride, KCl. 1 low much potassium chloride must be taken to produce 500 g of potassium perchlorate ... 

KC10, is made by heating potassium chlorate just to its melting point ... 

Its melting point is 10 C) and it is decomposed explosively by sunlight into chlorine and oxygen and ignites any combustible material in contact with it. Accordingly, when a drop of 60% or more cone, sulphuric acid is added to a mixture of potassium chlorate and sugar, it ignites instantaneously. 

In an autoclave or an iron pipe with a cap which can be screwed on (see page 64), heat a mixture of 10 parts commercial sodium anthraquinonemonosulphonate, 30 parts of sodium hydroxide, 1.8 parts of finely pulverised potassium chlorate, with 40 parts of water, for 20 hours to 170°. After cooling, the melt is boiled out with water several times, and acidified at the boiling-point of the solution in a large dish with concentrated hydrochloric acid. The alizarin separating out is then filtered off according to the quantity, either with suction or with the aid of a filter-press, washed with water, pressed out on a porous plate, and dried in an air-bath at 120°. In order to obtain it completely pure, it is distilled rapidly from a small retort, and is... 

Bowden and Singh [37, 38] achieved explosion of lead and silver azides when crystals were irradiated with an electron beam of 75 kV and 200 pA. Explosion was partly due to heating of the crystals by the electron beam. To substantiate this, crystals of potassium chlorate with a melting point of 334°C readily melted in the beam, showing a temperature rise close to the explosion temperature of the azides. Sawkill [97] investigated with an electron microscope the effect of an electron beam on lead and silver azides. If explosion did not take place, color changes and nucleation occurred cracks developed within the crystals which broke up into blocks about 10 cm across and were believed to be associated with a substructure in the crystals. In silver azide the progression to silver was pronounced but did not follow the thermal decomposition route. 

All the halates decompose on heating, usually above their melting point. In the presence of a transition metal catalyst such as Mn02, the decomposition of KCIO3 to chloride and oxygen starts at 70 °C and is the source of pure oxygen in laboratory preparation. In a series of the halates with the same cation, the thermal stability decreases in the sequence of [lOs]" > [0103] > [Br03] . Potassium chlorate is used in the mixture of safety matches, in pyrotechnic formulations, and as intermediates in the production of perchlorates. 

Noncombustible gas. Sulfur dioxide reacts violently with alkali metals at their melting points. Reactions with finely divided metals produce incandescence. Explosion occurs when it is mixed with fluorine or interhalogen compounds of fluorine. Incandescence occurs when carbides of alkali metals are placed in a sulfur dioxide atmosphere or by heating metal oxides with sulfur dioxide. An alcoholic or ethereal solution of sulfur dioxide explodes when mixed with powdered potassium chlorate (Mellor 1946). The dry gas reacts with chlorates to form chlorine dioxide, which ignites and explodes on heating. 

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