Potassium perchlorate, KCIO

In a balanced chemical equation, the number of atoms of each element on the left-hand, or reactant, side will equal the number of atoms of eaeh element on the right-hand, or product, side. The above equation states that one mole of potassium perchlorate (KCIO 4, a reactant) will react with 4 moles of magnesium metal to produce one mole of potassinm chloride (KCl) and 4 moles of magnesinm oxide (MgO). 

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 ... 

Potassium perchlorate (KCIO ) 757 Cl2Hgj(cr,l) Mercury chloride (HgCl2) 805... 

The equations for chemical reactions can be correctly written if the nature of the products is known. For example, in the reaction of a rocket propellant made of carbon and potassium perchlorate. KCIO., the products may be potassium chloride, KCl, and either carbon monoxide or carbon dioxide, or a mixture of the two. It would probably be wise to write two equations, corresponding to two reactions ... 

Potassium perchlorate KCIO 1.05 10-3 Zinc oxalate dihydrate ZnCjO 2HjO 1.38 10- ... 

Alkali Metal Perchlorates. The anhydrous salts of the Group 1 (lA) or alkah metal perchlorates are isomorphous with one another as well as with ammonium perchlorate. Crystal stmctures have been determined by optical and x-ray methods (38). With the exception of lithium perchlorate, the compounds all exhibit dimorphism when undergoing transitions from rhombic to cubic forms at characteristic temperatures (33,34). Potassium perchlorate [7778-74-7] KCIO, the first such compound discovered, is used in pyrotechnics (qv) and has the highest percentage of oxygen (60.1%). 

Procedure To the sample which contains 20-300 /xg of pertechnetate in 5-20 ml of solution, are added potassium perchlorate solution (2 ml, 1 mg KCIO per ml) and enough NaCl to make the solution approximately 1 M. The solution is heated and neutralized with ammonia. Pertechnetate is precipitated with aqueous 5 % tetraphenylarsonium chloride reagent. The precipitate is filtered, washed and dried, and a 2-mg portion is mixed with potassium bromide (300 mg). The mixture is pressed to form a clear disc by the usual technique. The infrared spectrum is recorded between 10 and 12 /x. The peak absorption is measured at 11.09 /X by the base-line technique. 

Table 6. 7 illustrates this same concept for the molybdenum / barium chromate /potassium perchlorate system. Here, KCIO 4 is the better oxidizer. 

Therefore, the initial choice for an oxidizer is one with an exothermic heat of decomposition such as potassium chlorate (KCIO 3). However, mixtures of both chlorate and perchlorate salts with active metal fuels are too ignition-sensitive for commercial use, and the less-reactive - but safer - nitrate compormds are usually selected. Potassium perchlorate is used with aluminum and magnesium in some "photoflash" mixtures these are extremely reactive compositions, with velocities in the explosive range. 

This material has gradually replaced potassium chlorate (KCIO 3) as the principal oxidizer in civilian pyrotechnics. Its safety record is far superior to that of potassium chlorate, although caution - including static protection - must stiU be used. Perchlorate mixtures, especially with a metal fuel such as aluminum, can have explosive properties, especially when present in bulk quantities and when confined. 

Potassium perchlorate is a white, non-hygroscopic crystalline material with a melting point of 6101C, considerably higher than the 356°C melting point of KCIO 3 It undergoes decomposition at high temperature... 

Chlorate. Potassium chlorate, [CAS 3811-04-9], chlorate of potash, KCIO, white solid, soluble, mp about 350°C, powerful oxidizing agent, and consequently a fire hazard with dry organic materials, such as clothes, and with sulfur upon heating oxygen is liberated and the residue is potassium chloride formed by electrolysis of potassium chloride solution under proper conditions, Used (l)m matches, (2) in pyrotechnics, (3) as disinfectant, (4) as a source of oxygen upon heating, (Hazardous Use of potassium perchlorate is recommended instead )... 

Ammonium chlorate decomposes gradually at room temperature. Needless to say compositions which contain ammonium perchlorate and potassium chlorate must be avoided. An experiment for producing ammonium chlorate by above reaction can be carried out as follows Add 35 grams of potassium chlorate, KCIO, to 100 ml. of water and dissolve it with heat. Add 36 grams of ammonium perchlorate, NH fClOi., to the solution and stir it well when a large quantity of white crystals will appear these are almost all potassium perchlorate. Leave it to cool to room temperature. Remove the crystals by filtration. The remaining liquid is mainly ammonium chlorate. Evaporate the mother liquor to about 30 ml. on a water bath. Cool it to room... 

Potassium or sodium chlorates (KC10 NaClO,) or perchlorates (KCIO, NaClO,) and diesel oil No.2... 

Potassium chlorate compositions are quite prone to accidental ignition, especially if sulfur or an acidic component or acidic impurity is also present. Chlorate-phosphorus mixtures are so sensitive and reactive that they can only be safely worked with when wet. The high hazard of KCIO, mixtures was gradually recognized in the late nineteenth century, and England banned aU chlorate-sulfur compositions in 1894. U.S. factories have greatly reduced their use of potassium chlorate as well, replacing it with the less sensitive potassium perchlorate in many formulas. 

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