NaOCl

Marsh s test for arsenic The arsenic-containing specimen is converted to volatile AsHs which is decomposed to a brown stain on heating. Estimation is by comparison of stains. Sb reacts similarly but the Sb stain is not soluble in NaOCl. 

NaOCl. Formed (with NaCl) from CI2 plus cold NaOH solution. Forms hydrates. Aqueous solutions are used as bleaches and antiseptics. 

CHsC,H SOeNCl, + 2NaOH = CH gCgH SOsNNaCl + NaOCl + H 0... 

Iodoform Reaction. To 0 5 ml. of ethanol add 3 ml. of 10% KI solution and 10 ml. of NaOCl solution. Warm gently fine yellow crystals of CHI3 separate. Isopropanol gives CHIj in the cold. Pure methanol and the other alcohols in this section go not give the reaction. 

A 25.00-mL sample of a liquid bleach was diluted to 1000 mb in a volumetric flask. A 25-mL portion of the diluted sample was transferred by pipet into an Erlenmeyer flask and treated with excess KI, oxidizing the OCh to Ch, and producing The liberated was determined by titrating with 0.09892 M NaySyOy, requiting 8.96 mb to reach the starch indicator end point. Report the %w/v NaOCl in the sample of bleach. 

Substituting for moles of NaOCl and SyOy leaves us with an equation 2 X grams NaOCl... 

Hoffman Degradation. Polyacrylamide reacts with alkaline sodium hypochlorite [7681-52-9], NaOCl, or calcium hypochlorite [7778-54-3], Ca(OCl)2, to form a polymer with primary amine groups (58). Optimum conditions for the reaction include a slight molar excess of sodium hypochlorite, a large excess of sodium hydroxide, and low temperature (59). Cross-linking sometimes occurs if the polymer concentration is high. High temperatures can result in chain scission. 

Chlorine reacts with alkaU and alkaline earth metal hydroxides to form bleaching agents such as NaOCl ... 

N—Fe(IV)Por complexes. Oxo iron(IV) porphyrin cation radical complexes, [O—Fe(IV)Por ], are important intermediates in oxygen atom transfer reactions. Compound I of the enzymes catalase and peroxidase have this formulation, as does the active intermediate in the catalytic cycle of cytochrome P Q. Similar intermediates are invoked in the extensively investigated hydroxylations and epoxidations of hydrocarbon substrates cataly2ed by iron porphyrins in the presence of such oxidizing agents as iodosylbenzene, NaOCl, peroxides, and air. 

Calcium Hypochlorite. This chemical, marketed since 1928, is one of the most widely used swimming-pool water sanitizers. Calcium hypochlorite, a crystalline sofld, is a convenient source of available chlorine and is sold in granular or tablet form for use in home, semiprivate, and commercial pools. When dissolved in water, Ca(OCl)2 forms hypochlorous acid and hypochlorite ion similar to NaOCl. It contains small amounts of stabilizing Ca(OH)2, which has a very small effect on pool pH (7). Calcium hypochlorite has superior storage stabiUty and much higher available CI2 concentration than Hquid bleach, which reduces storage requirements and purchasing frequency. 

Toxicity of Chlorine Sanitizers. Chlorine-based swimming-pool and spa and hot-tub sanitizers irritate eyes, skin, and mucous membranes and must be handled with extreme care. The toxicities are as follows for chlorine gas, TLV = 1 ppm acute inhalation LC q = 137 ppm for 1 h (mouse) (75). The acute oral LD q (rats) for the Hquid and soHd chlorine sanitizers are NaOCl (100% basis) 8.9 g/kg (76), 65% Ca(OCl)2 850 mg/kg, sodium dichloroisocyanurate dihydrate 735 mg/kg, and trichloroisocyanuric acid 490 mg/kg. Cyanuric acid is essentially nontoxic based on an oral LD q > 20 g/kg in rabbits. Although, it is mildly irritating to the eye, it is not a skin irritant. A review of the toxicological studies on cyanuric acid and its chlorinated derivatives is given in ref. 77. 

Sodium Hypochlorite. The principal form of hypochlorite produced is sodium hypochlorite [7681-52-9] NaOCl. It is invariably made and used as an aqueous solution and is usually prepared by the chlorination of sodium hydroxide solutions as shown in equation 9, though other bases such as sodium carbonate can be used (30). 

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. 

A 5—6% sodium hypochlorite solution is sold for household purposes, of which the largest use is in laundry. Solutions of 10—15% NaOCl are sold for swimming pool disinfection, institutional laundries, and industrial purposes. Solutions of various strengths are used in household and industrial and institutional (I I) cleaners, disinfectants, and mildewcides. A small amount is used in textile mills. Sodium hypochlorite is also made on site with 30—40 g/L available chlorine for pulp bleaching, but its use is decreasing in order to reduce chloroform emissions (see Chlorine oxygen acids and salts). 

Chlorinated Trisodium Phosphate. Chlorinated trisodium phosphate [11084-85-8] is a crystalline complex of hydrated trisodium orthophosphate and sodium hypochlorite that releases hypochlorite when mixed with water. Its formula is (Na PO 11H20)4 NaOCl. Commercial... 

NaOCL Sodium hypochlorite proves to be a useful reagent under PTC conditions for the following transformations (30) ... 

Dichlorine monoxide, generated in situ in the presence of CCl by reaction of CO2 and NaOCl, has been used in preparation of substituted hydra2ines (48). Dichlorine monoxide reacts with finely divided cyanuric acid in a fluidized bed forming dichloro- and trichloroisocyanuric acids (49) and with sodium cyanurate monohydrate yielding sodium dichloroisocyanurate monohydrate (50) (see Cyanuric and isocyanuric acids). 

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