Chloride ions chlorate

Pulp bleaching with chlorine dioxide is most often performed at an acidic pH, so that the final pH of the bleach Hquor is in the range of 2—5. Under these conditions, the residual concentration of chlorite and chlorate ions in the bleach Hquor are minimized and chloride ion is the predominant chlorine species in the spent bleach (77). In addition to direct addition to pulp in bleaching, chlorine dioxide also finds use in wastewater treatment from pulp mill operations as a means to remove effluent color (85). 

In the presence of added chloride, chlorate ion is formed in negligible amounts. 

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. 

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... 

A nanofiltration membrane will always allow the chloride and chlorate ions to pass... 

Divalent Pd forms many planar complexes with a coordination number of 4. The tetrachlorides aie quite soluble, When a solution of palladium(II) chloride is oxidized with chlorite or chlorate ion, Pd(IV) is formed, which has a coordination number of 8, The addition of NH4Q to such a solution precipitates ammonium hexachloropalladate(IV) as a red compound. It is somewhat less stable than the platinum analog. 

Solid chromium(lll) hydroxide, Cr(OH)3, reacts with aqueous chlorate ions, CIO3, in basic conditions to form chromate ions, CrO2, and chloride ions,Cl. ... 

Chlorate concentration increases during electrolysis, but exerts no influence upon the process, as its decomposition voltage is much higher than that of chloride. Chlorate ions are oxidized into perchlorate ions not sooner than tho chloride concentration in the electrolyte drops below 5 % of the initial value. Therefore, chlorate can accumulate in the solution up to the saturation. 

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 ... 

In solution hypochlorites disproportionate, slowly in cold but fast in hot solution, when chlorate and chloride ions are formed ... 

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... 

In PCI3, the chlorine atoms are covalently bonded to the phosphoms atom. In FeCl3, the chloride ions are ionically bonded to die iron(III) ion. In Fe(C103)3, the iron(III) ion is ionically bonded to die chlorate ion, and within the chlorate ion, the oxygen atoms are covalently bonded to the chlorine atom. In CI2, the chlorine atoms are covalently bonded to each other. 

Lipsztajn et al. produced chlorine dioxide gas from a sodium ehlorate, sodium chloride, and hydrochloric acid electrolyte [82]. A cation exchange membrane separated the two electrode compartments. The hydrogen ions, generated by water electrolysis on a dimensionally stable anode, migrate through the eation exchange membrane to the cathode, where they react chemically with sodium chlorate and chloride ions to form chlorine dioxide. 

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... 

We now check this equation on three points—change in oxidation number (6 electrons were used, corresponding to the change of —6 in oxidation number of chlorine from Cl in chlorate ion to Cl in chloride ion), conservation of electric charge (from — 1—64-6 to —1), and conservation of atomj—and convince ourselves that it is correct. 

Write electrode equations for the electrolytic production of (a) ferric ion from ferrous ion (b) magnesium metal frtmi molten magnesium chloride (c) perchlorate ion, CIO4—, from chlorate ion, CIOg, in aqueous solution ... 

The cadmium reductor has been used by Treadwell as a substitute for the zinc reductor. One application was the reduction of chlorate to chloride. Perchlorate was reduced to chloride only in the presence of a small amount of titanium ion as a catalyst. 

F. Winteler has studied the conditions favourable for the production of perchlorates, and found that if the concentration of the chloride exceeds 10 per cent., very little perchlorate will be formed in warm soln. The anode temp, should be kept low by artificial cooling, since the yield falls when the temp, is raised and it is preferable to have a high concentration of chlorate. In the electrolysis of alkali chloride soln., no perchlorate is formed until nearly all the chloride has been converted to chlorate. The yield is reduced in alkaline soln. probably owing to the smaller number of chlorate ions and the increasing number of hydroxyl ions liberated as the alkalinity is increased—hydroxyl ions are more easily discharged than chlorate ions. Increasing the current density counteracts the effect of increasing alkalinity. 

The active bleaching agent is the hypochlorite ion, which can decompose to chloride and chlorate ions in a side reaction that competes with bleaching ... 

A current passed through inert electrodes immersed in an aqueous solution of sodium chloride produces chlorate ion, C 03 aq), at the anode and gaseous hydrogen at the cathode. Given this fact, write a balanced equation for the chemical reaction if gaseous hydrogen and aqueous sodium chlorate are mixed and allowed to react spontaneously until they reach equilibrium. 

If a strong chemical reducing agent is added somewhere in the treatment process after chlorine dioxide primary disinfection, then chlorine dioxide and chlorite ions can be reduced to chloride ion. This would leave only traces of chlorate ion in the water. This chemical reduction technique will allow much higher chlorine dioxide dosages to be apphed for oxidation and/or primary disinfection than the 1.2-1.4 mg/L currently recommended. 

At present, granular activated carbon (GAC) or sulfur dioxide are known to chemically reduce chlorine dioxide and chlorite ion (but not chlorate ion) to the innocuous chloride ion. 

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