Sodium hypochlorate

Methoxy-N-chloromorphinan may be prepared in 78% yield by treatment of 3-methoxymorphinan with sodium hypochlorate.(139) Upon silver ion catalyzed rearrangement, it gave 13% of 146. The alkyl migration to the electron-deficient nitrogen was proposed as being mediated by a nitrenium ion transition state (145). 

Sodium bicarbonate Sodium bichromate Sodium carbonate Sodium chlorate Sodium cyanide Sodium ferrocyanide Sodium fluoride Sodium hypochlorate Sodium nitrate... 

Aged volume change, % after Immersion in Nitric Acid (70%) 14 Days at 24°C Sodium hypochlorate (20%) 28 days at 70°C... 

Wash it well with solution of Sodium HypoChlorate (NAOCIO3). 

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). 

Perchlorates. Historically, perchlorates have been produced by a three-step process (/) electrochemical production of sodium chlorate (2) electrochemical oxidation of sodium chlorate to sodium perchlorate and (4) metathesis of sodium perchlorate to other metal perchlorates. The advent of commercially produced pure perchloric acid directly from hypochlorous acid means that several metal perchlorates can be prepared by the reaction of perchloric acid and a corresponding metal oxide, hydroxide, or carbonate. 

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... 

In the reaction of aEyl alcohol with an aqueous chlorine solution, addition of hypochlorous acid to the double bond of aEyl alcohol yields glycerol monochlorohydrin and as a by-product, glycerol dichlorohydrin. Thus, a poor yield of glycerol monochlorohydrin is obtained (8). To improve the yield of glycerol monochlorohydrin, addition of sodium carbonate in an amount equivalent to that of the hydrogen chloride in the aqueous chlorine solution, has been proposed (9). 

Sodium hypochlorite and calcium hypochlorite are chlorine derivatives formed by the reaction of chlorine with hydroxides. The appHcation of hypochlorite to water systems produces the hypochlorite ion and hypochlorous acid, just as the appHcation of chlorine gas does. 

The dissociation of hypochlorous acid depends upon pH and, to a much lesser extent, temperature (6). At 25°C, it is - 0% at pH 5, about 50% at pH 7.5, and - 100% at pH 10, see Figure 1. Because of the acidity formed by chlorine gas, addition of soda ash (Na2C02) or sodium sesquicarbonate (Na2C03-NaHC03) is necessary to maintain the proper pH and to replenish alkalinity. 

Chlorine gas is usually used, but electrolysis of alkaline salt solutions in which chlorine is generated in situ is also possible and may become more important in the future. The final pH of solutions to be sold or stored is always adjusted above 11 to maximize stabiUty. The salt is usually not removed. However, when the starting solution contains more than 20.5% sodium hydroxide some salt precipitates as it is formed. This precipitate is removed by filtration to make 12—15% NaOCl solutions with about one-half of the normal amount of salt. Small amounts of such solutions are sold for special purposes. Solutions with practically no salt can be made by reaction of high purity hypochlorous acid with metal hydroxides. 

Hypochlorous acid can also be used, but the reaction is slower. Chlorine dioxide is also made by adding acid to sodium chlorite solutions by the overall reaction in equation 11 ... 

Hypochlorous Acid—Sodium Chlorite System. In this method, chlorine gas is educted into water forming a hypochlorous acid solution which then reacts with aqueous sodium chlorite to produce chlorine dioxide (114—116). Hypochlorous acid, formed from the disproportionation of chlorine gas in water ... 

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) ... 

The dissociation of hypochlorous acid depends on the pH. The unionized acid is present in greater quantities in acid solution, although in strongly acid solution the reaction with water is reversed and chlorine is Hberated. In alkaline solutions the hypochlorite ion OCL is increasingly Hberated as the pH is increased. The pH is important because unionized hypochlorous acid is largely responsible for the antimicrobial action of chlorine in water. Chlorine compounds are therefore more active in the acid or neutral range. The hypochlorites most commonly employed are sodium hypochlorite [7681-52-9] or calcium hypochlorite [7778-54-3]. 

Chlora.tes. Sodium chlorate is produced by the electrolysis of sodium chloride at pH 6.5—7.5 in a one-compartment cell. DSA anodes and steel cathodes are generally used in chlorate cells. The electrolysis products, hypochlorous acid, and hypochlorite ions, react chemically to produce chlorate (eq. 

A 3-1., three-necked flask fitted with a mechanical stirrer, a dropping funnel, and a thermometer is then charged with an aqueous solution of 2.2 moles of calcium hypochlorite [Hypochlorous acid, calcium salt] (Note 3), and the piperidine acetate prepared above is placed in the dropping funnel. The hypochlorite solution is stirred and cooled to 0° to — 5° with a methanol-ice bath, and the piperidine acetate is added dropwise over a period of 1.25 hours while the temperature is maintained below 0°. After a further 15 minutes of stirring, equal portions of the mixture are placed in two 2-1. separatory funnels and extracted three times with a total of about 1300 ml. of ether. The ether extract is placed in a 2-1. flask and dried over anhydrous sodium sulfate in a cold room at 4° overnight. After filtration to remove inorganic material, the bulk of the ether is removed by boiling on a water bath maintained below 60° (Note 4). 

Derbyshire and Waters202 carried out the first kinetic study, and showed that the chlorination of sodium toluene-m-sulphonate by hypochlorous acid at 21.5 °C was catalysed more strongly by sulphuric acid than by perchloric acid and that the rate was increased by addition of chloride ion. A more extensive examination by de la Mare et al.203 of the rate of chlorination of the more reactive compounds, anisole, phenol, and />-dimethoxybenzene by hypochlorous acid catalysed by perchloric acid, and with added silver perchlorate to suppress the formation of Cl2 and C120 (which would occur in the presence of Cl" and CIO-, respectively),... 

Kinetics studies of acid-catalysed chlorination by hypochlorous acid in aqueous acetic acid have been carried out, and the mechanism of the reactions depends upon the strength of the acetic acid an<( the reactivity of the aromatic. Different groups of workers have also obtained different kinetic results. Stanley and Shorter207 studied the chlorination of anisic acid by hypochlorous acid in 70 % aqueous acetic acid at 20 °C, and found the reaction rate to be apparently independent of the hydrogen ion concentration because added perchloric acid and sodium perchlorate of similar molar concentration (below 0.05 M, however) both produced similar and small rate increases. The kinetics were complicated, initial rates being proportional to aromatic concentration up to 0.01 M, but less so thereafter, and described by... 

Rather different experimental results were obtained by de la Mare et a/.208, 209, who studied chlorination by hypochlorous acid in 51, 75 and 98 % aqueous acetic acid. With the latter medium, the chlorination of anisole or m-xylene (at an unspecified temperature) was independent of the concentration of aromatic, and catalysed by perchloric acid to a much greater extent than an equimolar amount of lithium perchlorate the reaction was also catalysed by the base, sodium acetate. The reactive species was postulated as chlorine acetate produced... 

With 77 % aqueous acetic acid, the rates were found to be more affected by added perchloric acid than by sodium perchlorate (but only at higher concentrations than those used by Stanley and Shorter207, which accounts for the failure of these workers to observe acid catalysis, but their observation of kinetic orders in hypochlorous acid of less than one remains unaccounted for). The difference in the effect of the added electrolyte increased with concentration, and the rates of the acid-catalysed reaction reached a maximum in ca. 50 % aqueous acetic acid, passed through a minimum at ca. 90 % aqueous acetic acid and rose very rapidly thereafter. The faster chlorination in 50% acid than in water was, therefore, considered consistent with chlorination by AcOHCl+, which is subject to an increasing solvent effect in the direction of less aqueous media (hence the minimum in 90 % acid), and a third factor operates, viz. that in pure acetic acid the bulk source of chlorine ischlorineacetate rather than HOC1 and causes the rapid rise in rate towards the anhydrous medium. The relative rates of the acid-catalysed (acidity > 0.49 M) chlorination of some aromatics in 76 % aqueous acetic acid at 25 °C were found to be toluene, 69 benzene, 1 chlorobenzene, 0.097 benzoic acid, 0.004. Some of these kinetic observations were confirmed in a study of the chlorination of diphenylmethane in the presence of 0.030 M perchloric acid, second-order rate coefficients were obtained at 25 °C as follows209 0.161 (98 vol. % aqueous acetic acid) ca. 0.078 (75 vol. % acid), and, in the latter solvent in the presence of 0.50 M perchloric acid, diphenylmethane was approximately 30 times more reactive than benzene. 

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... 

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