Chlorate ions reactions

The standard potential for the anodic reaction is 1.19 V, close to that of 1.228 V for water oxidation. In order to minimize the oxygen production from water oxidation, the cell is operated at a high potential that requires either platinum-coated or lead dioxide anodes. Various mechanisms have been proposed for the formation of perchlorates at the anode, including the discharge of chlorate ion to chlorate radical (87—89), the formation of active oxygen and subsequent formation of perchlorate (90), and the mass-transfer-controUed reaction of chlorate with adsorbed oxygen at the anode (91—93). Sodium dichromate is added to the electrolyte ia platinum anode cells to inhibit the reduction of perchlorates at the cathode. Sodium fluoride is used in the lead dioxide anode cells to improve current efficiency. 

Large-Scale Industrial Production. Large amounts of chlorine dioxide ate used in pulp bleaching and smaller quantities ate used for the manufacture of sodium chlorite. In these appHcations, sodium chlorate is the only commercially available taw material. Chlorine dioxide production from sodium chlorate is achieved by the reduction of the chlorate ion in the presence of strong acid. The reaction consumes acid, so that acid and reducing agents must be constantly added to maintain the reaction. 

Chlorate Analysis. Chlorate ion concentration is determined by reaction with a reducing agent. Ferrous sulfate is preferred for quaHty control (111), but other reagents, such as arsenious acid, stannous chloride, and potassium iodide, have also been used (112). When ferrous sulfate is used, a measured excess of the reagent is added to a strong hydrochloric acid solution of the chlorate for reduction, after which the excess ferrous sulfate is titrated with an oxidant, usually potassium permanganate or potassium dichromate. 

C—O bonding and Cl—F fission of the intermediate cw-fluoro chlorate (29a), which in turn undergoes oxidation to the fluoro ketone (25) by a concerted elimination of chlorous acid. A similar transition state (30) approximating an allylic carbonium ion could be involved in the reaction of the dienol derivatives (6) with perchloryl fluoride, which would be expected to give rise to the c/5-adduct (30a). Reaction of the latter with water leads to product and chlorate ion. 

Charles, Jacques, 57 Charles law, 58 Chemical bonding, see Bonding Chemical bonds, see Bond Chemical change, 38 Chemical energy, 119 Chemical equations, see Equations Chemical equilibrium, law of, 152 Chemical formulas, see Formula Chemical kinetics, 124 Chemical reactions, see Reactions Chemical stability, 30 Chemical symbols, 30 not from common names, 31 see inside back cover Chemotherapy, 434 Chlorate ion, 360 Chloric acid, 359 Chlorides chemistry of, 99 of alkali metals, 93,103 of third-row elements, 103 Chlorine... 

It was observed by Gleu that chlorate ions can be rapidly reduced by arsenic-(III) during the reaction between arsenic(III) and cerium(IV). Csanyi and Szabo have established that induced reduction can be carried out by other 1-equivalent reagents, e.g. cobalt(III), manganese(III), permanganate while 2-equivalent reagents, e.g. bromine, chlorine, periodate, proved to be inactive. 

The pregnant solution is then treated with sulfur dioxide gas by which the reduction of the chlorate ions contained in the solution takes place according to the reaction ... 

In the presence of an oxidant, e.g., chlorate or bromate ions, the electrode reaction is transposed into an adsorption coupled regenerative catalytic mechanism. Figure 2.85 depicts the dependence of the azobenzene net peak current with the concentration of the chlorate ions used as an oxidant. Different curves in Fig. 2.85 correspond to different adsorption strength of the redox couple that is controlled by the content of acetonitrile in the aqueous electrolyte. In most of the cases, parabolic curves have been obtained, in agreement with the theoretically predicted effect for the surface catalytic reaction shown in Fig. 2.81. In a medium containing 50% (v/v) acetonitrile (curve 5 in Fig. 2.85) the current dramatically increases, confirming that moderate adsorption provides the best conditions for analytical application. 

Gordon G, Tachiyashik S. 1991. Kinetics and mechanisms of formation of chlorate ion from the hypochlorous acid/chlorite ion reaction at pH 6-10. Environ Sci Technol 25 468-474. 

Acids catalyze a variety of chemical reactions, even when present in small quantity. The presence of trace amounts of acidic materials in many high-energy compounds and mixtures can lead to instability. The chlorate ion, CIO3, is notoriously unstable in the presence of strong acids. Chlorate-containing mixtures will usually ignite if a drop of concentrated sulfuric acid is added. 

HC103. The end products of the secondary reaction following the discharge of the chlorate ions are therefore 2C103+H20=HC104+HC103. 

By diaphragms in a narrow sense we also understand a kind of partition which prevents as much as possible the diffusion of dissolved products of the electrolysis from one electrode to the other but must not hinder the passage of ions migrating under the influence of the electrical field in other words this partition should possess a high diffusion resistance but a low electrical resistance. Unless mutual diffusion and the mechanical mixing of anolyte and catholyte are prevented, i. e. on electrolyzing a solution of common salt, a mutual reaction occurs between the products of electrolysis, namely chlorine and hydroxide in which case hypochlorite ions are formed. They can then be converted, either electrochemically or chemically to chlorate ions. On separating both electrodes... 

In the limiting case, if all hydroxyl ions set free at the cathode would be transferred to the anode, a chemical reaction (see equation XI-13) would result between them and the whole amount of evolved chlorine with the subsequent electrochemical oxidation of hypochlorite ions to chlorate ions according to... 

The second reaction is due to hydrolysis of the dissolved chlorine which proceeds according to equations (XI-12) and (XI-13) under formation of hypo-chlorous acid and hypochlorite ions. As has already been stated hypochlorite ions are not stable products of electrolysis because they are easily oxidized at the anode to chlorate ions under the simultaneous evolution of oxygen [see equation (XI-14)] this occurs even at a relatively low concentration of hypochlorite ions. 

Also in an alkaline solution chlorate is the product of an electrochemical reaction. In this case hypochlorous acid formed by hydrolysis of the dissolved chlorine is neutralised in the immediate vicinity of the anode and the resulting hypochlorite ions are oxidized at the electrode to chlorate ions, as soon as formed (see equation (XVII-11)). Therefore, the concentration ot hypochlorite ions in the bulk of the solution with an alkaline electrolyte will be lower than in a neutral one. The current efficiency in a slightly alkaline solution may reach 66.67 per cent, but it decreases with rising alkalinity as a result of increasing hydroxyl ions discharge. However, if current efficiency approximating 60 per cent, which was normal in the first plants for electrochemical manufacture of chlorates, is acceptable, work with a moderately alkaline electrolyte will be the easiest. 

The standard potential of this reaction equals ept> ci-, 0107 = — 0.62 V. If we assume that the solution is neutral, and the activity a of both chloride and chlorate ions is unity, the following equation is valid at 25 °C according to Nernst s law ... 

Gordon, G. and Tachiyashiki, S. (1991) Kinetics and mechanism of formation of chlorate ion from the hypochlorous acid/chlorite ion reaction at pH 6-10. Environ. Sci. Technol. 25,468 174. Gordon, G., Gauw, R., Emmer, G. and Bubnis, B. (1998) The kinetics and mechanism of 003-formation following the electrolysis of salt brine What role do C102 and/or 03 play ACH-Models Chem. 135, 799-809. 

The net result is the disappearance of three hypochlorite ions, with formation of 1 chlorate ion and 2 chloride ions. Although apparently termolecular, the first reaction is unimoleeular, since the concentration of the hypochlorous acid remains constant. The second reaction is practically instantaneous.6 Chloride can be produced by the electrolysis of chlorate, possibly in accordance with the equation... 

This is the same as the net ionic equation given previously for the reaction of sodium chloride with silver nitrate because essentially the same reaction has taken place. Whether it was the sodium ions or the potassium ions or the nitrate ions or the chlorate ions that did not react is not important to us. In general, we can say that soluble ionic chlorides react with soluble silver salts to produce silver chloride. This statement does not mention the other ions present in the... 

If additives such as alkali metal chlorides, phosphates, tartrates, or citrates are added to the chlorite solution, chlorate ion (CIO3 ) formation is suppressed and chlorine dioxide is formed by the reaction ... 

Example L If potassium chlorate, KClOg, is dissolved in water dn,d o solution of ferrous salt, such as ferrous sulfate, FeS04, containing some sulfuric acid is added the chlorate ion is reduced to chloride ion and the ferrous ion is oxidized to ferric ion. Write the equation for liic reaction. 

Solution. The oxidation number of chlorine in chlorate ioii, CIO, is -f-5. The oxidation number of chlorine in chloride ion, Ci", is —1. Hence 6 electrons ait involvea in the - eduction of chlorate ion to chloride ion. The electron reaction is accord-ingly... 

At first sight there seems to be an anomaly in the reactions involving the free halogens and their oxygen compounds. Thus, although chlorine is able to liberate iodine from iodide ion, icxiine is able to liberate chlorine from chlorate ion,.according to the reaction... 

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