Potassium perchlorate, preparation

Iodide. A 0.01 M solution of potassium iodide, prepared from the dry salt with boiled-out water, is suitable for practice in this determination. The experimental details are similar to those given for bromide, except that the indicator electrode consists of a silver rod immersed in the solution. The titration cell may be charged with 10.00 mL of the iodide solution, 30 mL of water, and 10 mL of the stock solution of perchloric acid + potassium nitrate. In the neighbourhood of the equivalence point it is necessary to allow at least 30-60 seconds to elapse before steady potentials are established. 

Potassium perchlorate is prepared from potassium chlorate. Potassium chlorate, on heating, melts first and then resohdifies to potassium perchlorate ... 

The standard American flash and sound composition is a blend of potassium perchlorate, sulfur or antimony sulfide, and aluminum. The ignition temperature of this formulation is several hundred degrees higher than chlorate-based mixtures, but these are still very dangerous compositions because of their extreme sensitivity to spark and flame. Ignition of a small portion of a "flash and sound" mixture will rapidly propagate through the entire sample. These mixtures should only be prepared remotely, by experienced personnel. Table 8.5 hsts several "flash and sound" formulas. 

Berger et al. [93] reported preparation of n-Si (=10-100 nm) with the use of induction coupled plasma and scaled-up the process to kilogram level. The results of some formulations made with the use of this n-Si powder and potassium perchlorate prove their superior performance over the corresponding formulations based on micron-sized silicon powder. 

F. C. Mathers, and A. W. Kenney prepared perchloric acid by distilling a mixture of potassium perchlorate and sulphuric acid in a current of steam. H. H. Willard oxidized ammonium perchlorate with an excess of a mixture of nitric and hydrochloric acids. As a result, a mixture of perchloric, nitric, and hydrochloric acids is formed. The latter are expelled by heating the mixture on a hot plate until white fumes of perchloric acid begin to appear. No unoxidized ammonia should be present in the soln. An acid of a composition approximately HCIO4+2H2O, boiling at 203°, remains. 

Electrolytic processes for the perchlorates.—F. von Stadion found that if an aq. soln. of chlorine dioxide be included in Volta s circuit, at first very little gas is developed, but after some hours, oxygen and chlorine appear at the anode, and hydrogen at the cathode. The volume of hydrogen so obtained is nearly twice that of the oxygen. After some time the soln. is decolorized, and transformed into perchloric acid. In 1857, A. Riche 18 prepared perchloric acid by the electrolysis of hydrochloric acid, or of an aq. soln. of chlorine and ten years earlier, H. Kolbe prepared potassium perchlorate by the electrolysis of an aq. soln. of potassium chloride—acidified with sulphuric acid—and of potassium trichloro-methyl-sulphonate. H. Kolbe (1846), a pioneer in the electrolytic preparation of compounds, specially noted that the formation of perchloric acid is always preceded by that of chloric acid, and stated ... 

Perchlorate. Potassium perchlorate. [CAS 7778-74-7]. KCKU. white solid, very slightly soluble, mp 610°C, but above 400VC decomposes with evolution of oxygen gas and formation of potassium chloride residue formed (1) by electrolysis of potassium chlorate under proper conditions. (2) by heating potassium chlorate at 48(UC and then fractional crystallization. Used (1) as a convenient and safe (preferred to use of potassium chlorate) method of preparing oxygen by heating, (2) 111 the determination of potassium in soluble salt solution. 

Perchloryl fluoride, C103 F, has been prepared by the action of elemental fluorine on potassium perchlorate,1 by the electrolysis of sodium perchlorate in anhydrous hydrogen fluoride,2 and by reactions of various metal perchlorates with fluorosulfuric acid3 or antimony(V) fluoride.4 Although the latest methods (with HS03 F or SbFs or both) are more convenient than the first ones, they suffer the disadvantages that elevated temperatures are... 

In addition to the method outlined under procedure A, hydrazoic acid may be prepared by the action of oxalic1 or fluosilicic acids2 upon solutions of sodium azide or by the treatment of barium azide solutions with dilute sulfuric acid. A method involving the action of perchloric acid upon potassium azide has also been proposed. However, subsequent distillation of the filtrate, after removal of the precipitated potassium perchlorate, is necessary to prepare pure hydrazoic acid. Pure hydrazoic acid has also been obtained by the oxidation of hydrazine in acid solution by hydrogen peroxide.3-"... 

The chlorates, like the nitrates, are all readily soluble in water lead and silver chlorites, like the corresponding nitrites, are sparingly soluble salts and lead perchlorate is the only salt which does not easily dissolve. As already mentioned, chloric acid is readily decomposed when its aqueous solution is warmed chlorous acid is still less stable but perchloric acid, which may be prepared by distilling together potassium perchlorate with concentrated sulphuric acid, is relatively stable, seeing that it can be distilled without decomposition. It is an oily liquid, with acid taste it is apt to explode when brought into contact... 

For most potentiometric measurements either the saturated calomel reference electrode or the silver/silver chloride reference electrode are used. These electrodes can be made compact, are easily produced, and provide reference potentials that do not vary more than a few millivolts. The discussion in Chapter 5 outlines their characteristics, preparation, and temperature coefficients. The silver/silver chloride electrode also finds application in nonaqueous titrations, although some solvents cause the silver chloride film to become soluble. Some have utilized reference electrodes in nonaqueous solvents that are based on zinc or silver couples. From our own experience, aqueous reference electrodes are as convenient for nonaqueous systems as are any of the prototypes that have been developed to date. When there is a need to rigorously exclude water, double-salt bridges (aqueous/nonaqueous) are a convenient solution. This is true even though they involve a liquid junction between the aqueous electrolyte system and the nonaqueous solvent system of the sample solution. The use of conventional reference electrodes does cause some difficulties if the electrolyte of the reference electrode is insoluble in the sample solution. Hence the use of a calomel electrode saturated with potassium chloride in conjunction with a sample solution that contains perchlorate ion can cause erratic measurements due to the precipitation of potassium perchlorate at the junction. Such difficulties normally can be eliminated by using a double junction that inserts another inert electrolyte solution between the reference electrode and the sample solution (e.g., a sodium chloride solution). 

How could pure perchloric acid be prepared from potassium perchlorate ... 

After the electrolysis has been finished, solid sodium perchlorate may be separated from the solution, but usually other salts of perchloric acid are the final products, which are more suitable for commercial use. Potassium perchlorate is prepared by double decomposition of sodium perchlorate solution with potassium ehloride. If ammonium chloride or sulphate is used for the conversion, ammonium perchlorate will be obtained. Similarly, a mutual reaction with barium chloride will result in barium perchlorate. 

Summary This procedure is identical to method 1 and 2 expect the sodium perchlorate monohydrate is simply replaced with potassium perchlorate. The ammonium perchlorate is prepared by adding an ammonia solution to a hot dilute solution of potassium perchlorate, and then passing carbon dioxide into the solution over several hours to form potassium bicarbonate and ammonium perchlorate. After the reaction, the mixture is chilled, and then filtered to remove the potassium bicarbonate precipitate. The ammonium perchlorate remains in solution, and is then collected by reciystallization in the usual means. 

Method 1 Preparation of Potassium perchlorate from potassium chlorate... 

Summary Potassium perchlorate is readily prepared by fusing potassium chlorate in the presence of potassium chloride. The potassium chloride is used to decrease decomposition of the perchlorate and provide a stabilized uniform mixture. After the initial reaction, the potassium perchlorate is easily collected by thoroughly mixing the cooled mixture in water to dissolve the potassium chloride and any unreacted chlorate, followed by filtration to recover the insoluble perchlorate. 

Potassium perchlorate is insoluble in alcohol but soluble in water. It is prepared by reacting a soluble potassium salt with sodium perchlorate or perchloric acid. It is employed in pyrotechnics. 

The apparatus constant shall be determined as follows. First prepare the melting curves for pure tin, indium, potassium nitrate, and potassium perchlorate. Next using the value of heat of fusion found in the literature, determine the relationship between the temperature and the apparatus constant Calculate the apparatus constant at the extrapolated decomposition temperature, and, in the abovementioned equation, use the value so obtained. 

The salt can also be prepared by neutralizing perchloric acid with sodium hydroxide, but it is manufactured by the electrolytic oxidation of a 25 per cent, sodium-chlorate solution at 10° C., platinum electrodes and a high anode-potential being employed.1 This process finds application in the manufacture of potassium perchlorate, this salt being obtained from the sodium compound by the action of potassium chloride. 

The answer I found involved the use of potassium perchlorate. Although this chemical contains more oxygen than the derate, it is more stable In both storage and preparation. In addition, 1 found the sulfur could be eliminated entirely, making the preparation that much simpler. 

Uranyl Perchlorate, UOjlCIO lj.hHgO, is prepared by adding perchloric acid to a solution of potassium uranate, filtering off the precipitated potassium perchlorate, and evaporating the filtrate over phosphorus pentoxide. It forms yellow prismatic ciy stals, which melt at 90° C, and at 100° C. lose water, yielding the tetrahydrate, V0, C10,) AB. 0. 

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