Sodium bromate production

A typical polarographic recording is shown in Fig. 2.1 curve (a) is the po-larogram obtained for chlorinated seawater analysed immediately after chlorination. Identical traces were observed for non-chlorinated seawater and for chlorinated seawater kept in the dark for periods up to 24 h at temperatures up to 40 °C, which indicates a lack of bromate formation under these conditions (BrC>3 < 10 7 M, less than 0.5% conversion of chlorine). Addition of copper sulfate to give a cupric ion concentration in the seawater of 100 parts per billion did not induce measurable bromate production in the dark. Curve (b) was obtained from a chlorinated (4.9 mg/1) seawater solution that was exposed to full sunlight for 70 min. Curve (c), which is offset by 0.4 pA with respect to curves (a) and (b), shows the presence of 1.0 x 10 5 M sodium bromate in seawater. 

Even though the reaction conditions may lead to formation of the metal enolate in high yield, further reduction may occur during the quenching step of the reaction. Alcohols such as methanol and ethanol convert metal enolates to saturated ketones much faster than they react with metals in ammonia, and quenching of reduction mixtures with these alcohols will usually lead to partial or complete conversion to alcoholic product rather than to the saturated ketone. Rapid addition of excess solid ammonium chloride is the commonly employed quench procedure if ketonic products are desired,but other reagents that destroy solvated electrons before neutralization may be employed, such as sodium ben-zoate, iron(III) nitrate, - sodium nitrite, bromobenzene, sodium bromate, 1,2-dibromoethane and acetone. 

The neutralizers of hair straighteners are similar to those of permanent-waving products. The thiol-based products usually use an oxidizing system based generally on hydrogen peroxide or sodium bromate, whereas the... 

The liberated bromine is carried by a stream of air into an alkaline solution of sodium carbonate where it dissolves as a mixture of bromide and bromate [the analogy of reaction (79)]. This last step serves to concentrate the product, and free bromine is obtained by subsequent acidification of the solution, through the reaction... 

Another method involves adding excess bromine to a solution of sodium hydroxide. This forms sodium bromide andbromate. The product solution is evap-oated to dryness. The bromate is reduced to bromide by heating with carbon 3Br2 + 2NaOH + H2O NaBr + NaBrOs -1- 4HBr... 

Hydrofluoric acid like water is an associated liquid, and even the gas, as we shall soon see, is associated. It has the power of uniting with fluorides. It also seems to be an ionizing solvent for a soln. of potassium fluoride in liquid hydrogen fluoride is an excellent conductor it also possesses marked solvent powers. According to E. C. Franklin,7 the liquid readily dissolves potassium fluoride, ehloride, and sulphate sodium fluoride, bromide, nitrate, chlorate, and bromate acetamide and urea. The solvent action is not so marked with barium fluoride, cupric chloride, and silver cyanide while calcium and lead fluorides copper sulphate and nitrate ferric chloride, mercuric oxide, and magnesium metal, are virtually insoluble in this menstruum. Glass also is not affected by the liquid if moisture be absent. The liquid scarcely acts on most of the metals or non-metals at ordinary temp., though it does act on the alkali metals at ordinary temp., much the same as does water, with the simultaneous production of flame. 

A. J. Balard 6 prepared a soln. of sodium hypobromite, NaOBr, by working in a similar manner to the process employed for the hypochlorite. When bromine is gradually added to soda lye, the bleaching power increases up to a maximum, and after that decreases owing to the conversion of the hypobromite into bromate. A. J. Balard also described a similar product, potassium hypobromite, obtained by the action of bromine on potassium carbonate. 

Extraction of the elemental form of bromine is used to separate short-lived bromine activities from fission products. Potassium chlorate in 8 N nitric acid solution (255)s potassium permanganate in nitric acid solution (106,248), and a bromlde-bromate-hypofchlorite mixture in acidic solution (247) have been used as the oxidizing agent. The bromine is extracted into carbon tetrachloride and can be back-extracted into the aqueous solution by reducing agents, such as potassium nitrate (255)> hydrazine hydrochloride (106,248), or sodium hydrosulphite (106). 

After the oxidation, the sodium, fluoride, and excess bromate must be removed to obtain a pure product. The bulk of the bromate and fluoride are precipitated with barium, and the sodium is removed with cation exchange resin. After concen-... 

The determination of propiolactone with thiosuUate has been described by T ler and Reering it cannot as a rule be applied to the homologs (see section VI.4.C ). The determination of acrylic add with a mixture of potassium bromate and hromide and that of the total acidity by direct -titrstion with sodium methylate in anhydrous methanol have been discussed in the booklets edited by members of the Celanese Corporation of America, They recommend mass cpeciro-graphy for the evaluation of the lactons content of oommerical products and for the detection of certain impurities. 

Br 77.65%, Na 22.35%. NaBr. Prepd commercially by adding some excess bromine to a sodium hydroxide soln forming a mixture of bromide and bromate. The reaction products are evaporated to dryness and treated with carbon to reduce the bromate to bromide. Ref van ter Meulen, U.S. pat. 1,775,598 (1930) Robertson, Ind, Eng. Chem. 34, 133 (1942) T O. Some, C O. Wilson, Roger s Inorganic Pharmaceutical Chemistry (Lea Sl Febiger, Philadelphia, 8th ed., 1967) pp 213-216. 

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