Sodium perchlorate, decomposition

The U.S. domestic capacity of ammonium perchlorate is roughly estimated at 31,250 t/yr. The actual production varies, based on the requirements for soHd propellants. The 1994 production ran at about 11,200 t/yr, 36% of name plate capacity. Environmental effects of the decomposition products, which result from using soHd rocket motors based on ammonium perchlorate-containing propellants, are expected to keep increasing pubHc pressure until consumption is reduced and alternatives are developed. The 1995 price of ammonium perchlorate is in the range of 1.05/kg. Approximately 450 t/yr of NH ClO -equivalent cell Hquor is sold to produce magnesium and lithium perchlorate for use in the production of batteries (113). Total U.S. domestic sales and exports for sodium perchlorate are about 900 t/yr. In 1995, a solution containing 64% NaClO was priced at ca 1.00/kg dry product was also available at 1.21/kg. 

The perchlorates are prepared by the action of the acid on a suitable base, by the thermal decomposition of certain chlorates, and by the electrolysis of chlorates. Perchloric acid is always monobasic no acid salts have been made. Sodium perchlorate has been reported in the nitrates of Chili. According to M. H. Marker,1 some specimens have up to 5-64 per cent, of this salt, and it has been suggested that the presence of perchlorates is the cause of the deleterious action of some deliveries of Chili saltpetre when used as a fertilizer for rye. 

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. 

Sodium perchlorate forms whitish to colorless deliquescent monohydrated crystals with a decomposition temperature of 130 Celsius. The crystals are very soluble in water, but have limited solubility in the usual solvents. 

In order to lower the freezing point (to about — 30 °C), high concentrations e.g. 800 g.l ) of sodium perchlorate were frequently used in this work. Decomposition of monothiocarbonate probably involves attack of water on the... 

Manufacture. At first sodium chlorate is prepared by the electrolysis of industrial salt or the milk of lime process described in (2). The sodium chlorate is further electrolyzed to produce sodium perchlorate, and when potassium chloride is added to cause double decomposition, crude potassium perchlorate is obtained. This is recrystallized and crushed to powder. It is impossible to obtain potassium perchlorate by the direct electrolysis of potassium chlorate, because of the low solubility of potassium. perchlorate in water. 

Long and his co-workers (Long, Dunkle, and McDevit, 75) have used the acidity function to decide whether or not a water molecule is present in the activated complex in the acid-catalyzed hydrolysis of 7-butyro-lactone. They found no correlation with Ho and therefore conclude that the water molecule is present in the activated complex. This is in contrast to their findings for the hydrolysis of /S-propiolactone. Paul (76) has studied the decomposition of trioxane in mixtures of perchloric acid and sodium perchlorate at constant perchlorate concentration (6 M) and found good correlation with the acidity function as determined by Harbottle (77). 

Electrocatalysis can modify the composition of the electrode surfaces and the nature of the electrolytic products. The perchlorate decomposition (cathodic production of chloride) on platinum catalysts is one of the examples [57] and the IrCT decomposition during the sodium chlorate production [58]. The electropolymerization of the organic substances is critically dependent on the type of the electronic/ionic conductors, electrolyte characteristics, and the electrolysis resident time of the monomer [59]. 

Perchlorates are made commercially by the electrolytic oxidation of chlorates. Sodium perchlorate is made first as a rule, and other perchlorates are prepared from it by double decomposition. The conditions for a good yield of perchlorate are concentrated neutral chlorate solution, temperature below 50°, current density 0.1 amp/cm or more, and anode of platinum. Platinum is better than graphite, probably because of its higher oxygen overvoltage. 

In polyacrylonitrile appreciable electrostatic forces occur between the dipoles of adjacent nitrile groups on the same polymer molecule. This restricts the bond rotation and leads to a stiff, rodKke structme of the polymer chain. As a result, polyacrylonitrile has a very high crystalline melting point (317°C) and is soluble in only a few solvents, such as dimethylformamide and dimethylacetamide, and in concentrated aqueous solutions of inorganic salts, such as calcium thiocyanate, sodium perchlorate, and zinc chloride. Polyacrylonitrile cannot be melt processed because its decomposition temperature is close to the melting point. Fibers are therefore spun from solution by either wet or dry spinning (see Chapter 2). 

Perchlorate is always made as the sodium salt and potassium and ammonium perchlorate is then prepared by double decomposition. The electrolyte is sodium chlorate (300—700 g 1 ) at a pH between 0 and 1 and sodium perchlorate is also often present in the cell feed to ease isolation of the product. The anode is... 

This complex was found to constitute 20 % of the hydrolysis mixture and can be eluted from the column with 0.6 M sodium perchlorate solution adjusted to pH 2.0. A chromium to cyanide ratio of 1 1.00 was determined by analysis for this pink, permanganate-colored species. The visible and ultraviolet spectrum of cyanopentaaquochromium(III) ion is independent of pH in the regions from 2 to 3.5 and is included in Fig. 4. The positions of the maxima (in mp) and corresponding molar absorbancy indices (in / mole cm ) in 0.6M sodium perchlorate are 525 (26.0), and 393 (20.5). The strong absorption band in the ultraviolet shows a point of inflection a = 268 I mole" cm" ) at 235 mp. The positions of the absorption maxima are identical to those reported by Espenson. Dilute solutions (pH 2) of the monocyano complex can be stored at 0° for several days without serious decomposition. 

Chemical Properties. On thermal decomposition, both sodium and potassium chlorate salts produce the corresponding perchlorate, salt, and oxygen (32). Mixtures of potassium chlorate and metal oxide catalysts, especially manganese dioxide [1313-13-9] Mn02, are employed as a laboratory... 

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