Hypochlorous acid, oxidation with

Cyanate can be further oxidized by HOCl to nitrogen and bicarbonate along with small amounts of N2O and NCl. Hypochlorous acid reacts with peroxide with evolution of oxygen by the postulated intermediate formation of peroxyhypochlorous acid (99). 

Iodoxybenzene has been prepared by the disproportionation of iodosobenzene,4Hi by oxidation of iodosobenzene with hypo-chlorous add or bleaching powder,7 and by oxidation of iodobenzene with hypochlorous acid or with sodium hydroxide and bromine.8 Other oxidizing agents used with iodobenzene include air,3 chlorine in pyridine,9 Caro s acid,19-11 concentrated chloric acid,15 and peracetic acid solution.13 Hypochlorite oxidation of iodobenzene dichloride has also been employed.14... 

The hypochlorous acid oxidizes the cell walls and kills bacteria. Solid calcium hypochlorite, Ca(OCl)2, and liquid solutions of sodium hypochlorite, NaOCl, can be used to generate hypochlorous acid in place of chlorine gas, for example, in chlorinating swimming pools. The hypochlorite ion generated from Ca(OCl)2 and NaOCl forms an equilibrium with water represented by the equation ... 

Chlorine, derived from a mixture of hydrochloric acid and potassium bichromate in a 1500 c.c. flask, is washed in water, and then led into a 500 c.c. flask containing mercuric oxide covered with five times its volume of water. The flask is fitted with a stopper carrying an inlet tube reaching nearly to the bottom, and an exit tube connected with a fume chamber. This flask stands in water cooled with ice. When the reaction is nearly completed, the mercuric oxide disappears. The flask is agitated periodically. The soln. of hypochlorous acid mixed with mercuric oxide, etc., is distilled the receiver should be connected with the fume chamber. 

Thermochemistry of the oxychlorine acids.—Perchloric acid is not so powerful an oxidizing agent as chloric acid, and this in turn is less vigorous than hypochlorous acid. This agrees with the stability of the respective acids, and is in accord with the fact that a greater amount of available energy per atom of available oxygen is associated with hypochlorous acid than with either chloric or perchloric acid. For instance, the thermochemical equations are represented ... 

This is essentially a two-step reaction, with hypochlorous acid being generated from the reaction of bleach with water and then the hypochlorous acid oxidizing the sodium bromide component. 

The unique property of MPO among the mammalian oxidizing enzymes is that MPO-compound I possesses a high enough oxidative potential to oxidize the chloride ion (Cl-) to hypochlorous acid (HOC1) with re-formation of the native enzyme (A3, H9, S54, Z3) ... 

Iodoxybenzene has been prepared by oxidizing iodobenzene with Caro s acid 2 by treating iodobenzene with hypochlorous acid or with aqueous sodium hydroxide and bromine 3 by action of chlorine upon iodobenzene dissolved in pyridine 4 by oxidation... 

A similar intramolecular oxidation, but for the methyl groups C-18 and C-19 was introduced by D.H.R. Barton (1979). Axial hydroxyl groups are converted to esters of nitrous or hypochlorous acid and irradiated. Oxyl radicals are liberated and selectively attack the neighboring axial methyl groups. Reactions of the methylene radicals formed with nitrosyl or chlorine radicals yield oximes or chlorides. 

Ethylene glycol was originally commercially produced in the United States from ethylene chlorohydrin [107-07-3J, which was manufactured from ethylene and hypochlorous acid (eq. 8) (see Chlorohydrins). Chlorohydrin can be converted direcdy to ethylene glycol by hydrolysis with a base, generally caustic or caustic/bicarbonate mix (eq. 9). An alternative production method is converting chlorohydrin to ethylene oxide (eq. 10) with subsequent hydrolysis (eq. 11). 

Chlorine and Bromine Oxidizing Compounds. The organo chlorine compounds shown in Table 6 share chemistry with inorganic compounds, such as chlorine/77< 2-3 (9-j5y and sodium hypochlorite/7 )< /-j5 2-5 7. The fundamental action of chlorine compounds involves hydrolysis to hypochlorous acid (see Cm ORiNE oxygen acids and salts). 

Oxidation. There are 10 types of oxidative reactions in use industriaHy (80). Safe reactions depend on limiting the concentration of oxidi2ing agents or oxidants, or on low temperature. The foUowing should be used with extreme caution salts of permanganic acid hypochlorous acid and salts sodium... 

Cooling water pH affects oxidizing antimicrobial efficacy. The pH determines the relative proportions of hypochlorous acid and hypochlorite ion or, in systems treated with bromine donors, hypobromous acid and hypobromite ion. The acid forms of the halogens are usually more effective antimicrobials than the dissociated forms. Under some conditions, hypochlorous acid is 80 times more effective in controlling bacteria than the hypochlorite ion. Hypochlorous acid predominates below a pH of 7.6. Hypobromous acid predominates below pH 8.7, making bromine donors more effective than chlorine donors in alkaline cooling waters, especially where contact time is limited. 

Dichlorine monoxide is the anhydride of hypochlorous acid the two nonpolar compounds are readily interconvertible in the gas or aqueous phases via the equilibrium CI2 O + H2 0 2H0Cl. Like other chlorine oxides, CI2O has an endothermic heat of formation and is thus thermodynamically unstable with respect to decomposition into chlorine and oxygen. Dichlorine monoxide typifies the chlorine oxides as a highly reactive and explosive compound with strong oxidhing properties. Nevertheless, it can be handled safely with proper precautions. 

Hypochlorous acid reacts very rapidly and quantitatively with a slight excess of free ammonia forming monochloramine, NH2CI, which reacts at a slower rate with additional HOCl forming dichloramine, NHCI2. Trichloramine is formed when three moles of HOCl are added per mole of ammonia between pH 3—4 (100). Hypochlorous acid in the form of chlorine or hypochlorite is used in water treatments to oxidize ammonia by the process of break-point chlorination, which is based on formation of unstable dichloramine. The instabiHty of NHCI2 is caused by presence of HOCl and NCl (101,102). The reaction is most rapid at a pH of about 7.5 (103). Other nitrogen compounds such as urea, creatinine, and amino acids are also oxidized by hypochlorous acid, but at slower rates. Unstable iV-chloro compounds are intermediates in deammination of amino acids (104,105). 

Hypochlorous acid undergoes a variety of reactions with organic substances including addition, oxidation, C- and iV-chlorination, and ester formation. On an industrial scale, hypochlorous acid, generated m situ via chlorine hydrolysis, reacts with propylene forming primarily the a-propjlene chlorohydrin isomer. 

Molten sodium cyanide reacts with strong oxidizing agents such as nitrates and chlorates with explosive violence. In aqueous solution, sodium cyanide is oxidized to sodium cyanate [917-61 -3] by oxidizing agents such as potassium permanganate or hypochlorous acid. The reaction with chlorine in alkaline solution is the basis for the treatment of industrial cyanide waste Hquors (45) ... 

Ethylene oxide has been produced commercially by two basic routes the ethylene chlorohydrin and direct oxidation processes. The chlorohydrin process was first iatroduced dufing World War I ia Germany by Badische Anilin-und Soda-Eabfik (BASE) and others (95). The process iavolves the reaction of ethylene with hypochlorous acid followed by dehydrochlofination of the resulting chlorohydrin with lime to produce ethylene oxide and calcium chloride. Union Carbide Corp. was the first to commercialize this process ia the United States ia 1925. The chlorohydrin process is not economically competitive, and was quickly replaced by the direct oxidation process as the dominant technology. At the present time, all the ethylene oxide production ia the world is achieved by the direct oxidation process. 

It should be noted that although BrCl is mainly a brominating agent that is eompetitive with bromine, its ehemieal reaetivity makes its action similar to that of ehlorine (that is, disinfection, oxidation, and a bleaching agent). BrCl hydrolyzes exelusively to hypobromous aeid, and if any hydrobromie aeid (HBr) is formed by hydrolysis of the dissociated bromine, it quickly oxidizes to hydrobromous acid via hypochlorous acid. 

The hypochlorous acid, HCIO, formed by this reaction is a powerful oxidizing agent (E a = +1.630 V) it kills bacteria, apparently by destroying certain enzymes essential to their metabolism. The taste and odor that we associate with chlorinated water are actually due to compounds such as CH3NHC1, produced by the action of hypochlorous acid on bacteria. 

The acid strengths and oxidizing abilities of the halogen oxoacids increase with the oxidation number of the halogen. The hypohalous acids, HXO (halogen oxidation number +1), are prepared by direct reaction of the halogen with water. For example, chlorine gas disproportionates in water to produce hypochlorous acid and hydrochloric acid ... 

Degradation of the insecticide chlorpyrifos has been examined in solutions of aqueous chlorine in which the primary oxidant is hypochlorous acid/hypochlorite. The final product was 2,3,5-trichloropyrid-2-one produced either directly, or via initial oxidative conversion of the thioate ester by replacement of the sulfur with oxygen (Duirk and Collette 2006). An analogous oxidation was found with diazinon (Zhang and Pehkonen 1999). 

An alternative to the direct anodic oxidation of organic contaminants are the methods of indirect oxidation with the aid of oxidizers formed electrochemically in situ. These oxidizers (or mediators) can be obtained in both anodic and cathodic processes. Anodic agents are the salts of hypochloric acid (hypochlorites), the permanganates, the persulfates, and even ozone. 

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