Hypochlorite sodium

Sodium hypochlorite (SO-dee-um hye-po-KLOR-ite) is the active ingredient in liquid chlorine bleaches, used in the home and many industries to whiten fabric and other materials and to disinfect surfaces and water. The anhydrous compound is very unstable and explodes readily. The pentahydrate is a pale-green crystalline solid that is relatively stable. The compound is usually made available as an aqueous solution that contains anywhere from 3 to 6 percent sodium hypochlorite (for household use) to as high as 30 percent (for industrial applications). In solution form, sodium hypochlorite is quite stable and can be stored for long periods of time out of sunlight. 

Sodium hypochlorite decomposes by two mechanisms. In one case, it breaks down to form sodium chloride and sodium chlorate  

Sodium hypochlorite. Red atom is oxygen green atom is chlorine and turquoise atom is sodium. PUBLISHERS RESOURCE GROUP 

Nascent oxygen is a very active form of oxygen that is responsible for the bleaching and disinfectant properties of sodium hypochlorite. 

Sodium hypochlorite is usually sold in solution in water, where it makes a greenish-yellow liquid. (It is too hygroscopic—it absorbs water from the air—to be used conveniently in solid form.) Household bleaches usually contain sodium hypochlorite in a 3 percent to 6 percent solution. Some sodium hydroxide (lye) is added to keep the pH high to avoid decomposition. If the solution is made more acidic, sodium hypochlorite will dissociate, producing chlorine gas and oxygen. 

Sodium hypochlorite is made by bubbling chlorine gas through a solution of sodium hydroxide. In the environment, it breaks down into water, oxygen, and table salt. 

Sodium hypochlorite is the main ingredient in laundry bleach. Despite the fact that it is commonly referred to as chlorine bleach, in normal use there is no chlorine gas involved in the action of bleaching or disinfecting. 

Sodium hypochlorite is one of the best disinfectants known, capable of killing bacteria, yeasts, fungus, spores, and even viruses. Because it is an excellent disinfectant as well as a bleaching agent, it is used in many household cleaners. Sodium hypochlorite is also used to disinfect water supplies and swimming pools (although calcium hypochlorite in powder or pellet form is often used as a substitute, due to the convenience of its solid form). 

Sodium hypochlorite is a sodium salt of hypochlorous acid (HOCl). Sodium hypochlorite can be prepared by passing chlorine gas into a tank containing pre- 

Sodium hypochlorite solution is strongly alkaline (pH = 11.55) and the free caustic present in the solution acts as a stabiliser. Soda-ash scavanges free hydrochloric acid forming a non-volatile salt and maintain its alkalinity. Stability of sodium hypochlorite solution is also improved by storing it in a dark room below 30°C and free from contaminations of any heavy metal salts. The decomposition of sodium hypochlorite can be represented by the following reactions  

2NaOCl - NaCl + NaClO, or 2NaOCl 2NaCl + Oj t or 3NaOCl 2NaCl + NaC103 

The bleaching mechanism of sodium hypochlorite consists of the following reaction [2]  

The above reaction is accompanied by severance of glucose linkage in cotton, resulting in loss of tensile strength. 

CHEMICAL NAME = sodium hypochlorite CAS NUMBER = 7681-52-9 MOLECULAR FORMULA = NaOCl MOLAR MASS = 74.4 g/mol COMPOSITION = Na(30.9°/o) Cl(47.6%) 0(21.5%) 

Bleaching powders, borax, lye, and blueing were used as bleaches throughout the 19th century. In the second half of the 19th century, the acceptance of Louis Pasteurs (1822-1895) 

Sodium hypochlorites (and calcium hypochlorite s) disinfection property is due to its ability to form hypochlorous acid, HOC1. The hypochlorous acid oxidizes the cell walls and kills bacteria. Sodium hypochlorite generates hypochlorous acid according to the reaction NaOCl( H2offi — HOCl + NaOH(Ml. The hypochlorite ion generated from NaOCl exists 

Sodium hypochlorite is the primary hypochlorite used as a bleach and disinfectant, accounting for 83% of world hypochlorite use, with calcium hypochlorite accounting for the remaining 17%. Approximately 1 million tons of sodium hypochlorite was used globally in 2005, with about half this amount used in households for laundry bleaching and disinfection. The other half was used primarily for wastewater and drinking water treatment other uses include pool sanitation, bleaching of pulp, paper, and textiles, and as an industrial chemical. 

The relation between the oxidation power of gaseous chlorine and that of bleaching agents will be found in equations of their respective reduction processes when related to an equal number of electrons consumed. The reduction of chlorine proceeds according to the equation 

From these equations it is evident that 1 mole of chlorine has the same oxidation power as one gram-ion of CIO- (i. e. one mole of NaCIO or half a mole of Ca(C10)2), half a inole of NaC102. or finally, two fifths of a mole of chlorine dioxide. For example, one gram-molecule of pure calcium hypochlorite of 142.99 grams in weight has the same bleaching power as two moles of chlorine weighing 141.84 g. The content of active chlorine in this substance thus equals 141.84/142.99 = 99.19 per cent. 

Sodium hypochlorite is a white hygroscopic substance the probable composition of which corresponds to the formula NaOCl. 6 H20. This compound is very unstable and decomposes easily under liberation of oxygen due to this fact the preparation of crystaline salt is very expensive, so for technical purposes it is produced only as an aqueous solution. This can be done either by electrolysis or chemically by gaseous chlorine being introduced into a solution of sodium 

that would be hydrogen peroxide, as in a peroxide blonde (see p245). 

that s also hydrogen peroxide, or a diluted version of it in the form of carbamide peroxide. 

Household bleach is actually a mixture of chemicals. Its main constituent is a solution of 3-6% sodium hypochlorite (NaOCl), 

Sodium hypochlorite is used on a huge scale in agriculture, and areas such as chemical, paint, lime, food, glass, paper, pharmaceuticals, synthetics and waste disposal industries. It is often added to industrial waste water to reduce odors, since NaOCl neutralizes HgS and ammonia. It is also used to detoxify the cyanide baths used in 

When you swim in a public swimming pool, you re actually swimming through a dilute bleach solution  

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It is prepared by the action of sodium hydroxide and sodium hypochlorite on phthalimide (Hofmann reaction). When heated with soda lime it gives aniline. 

The reactions involved are similar in both cases, and closely parallel to those which give rise to chloroform. The sodium hypochlorite probably first oxidises the potassium iodide to potassium hypoiodite, which then oxidises the ethanol to acetaldehyde and then iodinates the latter to tri-iodo ... 

IODOFORM FROM ACETONE. (Semi-micro Scale.) Required Acetone, 0 5 ml. 10% potassium iodide solution, 20 ml. 10% sodium hydroxide solution, 8 ml. zM sodium hypochlorite solution, 20 ml. 

Place 0 5 ml. of acetone, 20 ml. of 10% aqueous potassium iodide solution and 8 ml. of 10% aqueous sodium hydroxide solution in a 50 ml. conical flask, and then add 20 ml. of a freshly prepared molar solution of sodium hypochlorite. Well mix the contents of the flask, when the yellow iodoform will begin to separate almost immediately allow the mixture to stand at room temperature for 10 minutes, and then filter at the pump, wash with cold w ater, and drain thoroughly. Yield of Crude material, 1 4 g. Recrystallise the crude iodoform from methylated spirit. For this purpose, place the crude material in a 50 ml. round-bottomed flask fitted with a reflux water-condenser, add a small quantity of methylated spirit, and heat to boiling on a water-bath then add more methylated spirit cautiously down the condenser until all the iodoform has dissolved. Filter the hot solution through a fluted filter-paper directly into a small beaker or conical flask, and then cool in ice-water. The iodoform rapidly crystallises. Filter at the pump, drain thoroughly and dry. 

Dichloramine-T. Dilute 80 ml, of freshly prepared 2N sodium hypochlorite soluticMi (preparation, p. 525) with 80 ml. of w ter, and then add with stirring 5 g. of finely powdered toluene-p-sulphonamide, a clear solution being rapidly obtained. Cool in ice-water, and then add about 50 ml. of a mixture of equal volumes of glacial acetic acid and water slowly with stirring until precipitation is complete the dichloro-amide separates at first as a fine emulsion, which rapidly forms brittle colourless crystals. Filter off the latter at the pump, wash well with... 

Iodoform reaction. To i ml. of the aldehyde solution, add 3 ml. of 10% KI solution and 10 ml. of freshly prepared sodium hypochlorite solution. Yellow crystals of iodoform, CHI3, soon separate. 

Acetone (R = CHj) when treated with sodium hypochlorite or bleaching powder solution yields chloroform, probably in accordance with the following mechanism ... 

The commercial 10-14 per cent, sodium hypochlorite solution should be diluted with an equal volume of water. 

By treatment of an amide with sodium hypobromite or sodium hypochlorite solution (or with the halogen and alkali), the amine of one less carbon atom is produced, the net result being the elimination of the carbonyl group. An example is ... 

Anthranilic acid. This substance, the ortho amino derivative of benzoic acid, may be conveniently prepared by the action of sodium hypobromite (or sodium hypochlorite) solution upon phthalimide in alkaline solution at 80°. The ring in phthalimide is opened by hydrolysis to phthalamidic acid and the latter undergoes the Hofmann reaction (compare Section 111,116) ... 

The reactivity of the amino radical has not yet been investigated. Alkaline hypochlorite oxidation, known in the pyridine series to yield azo derivatives (155,156). and photolysis of N,N-dichloro derivatives, which may be obtained by action of sodium hypochlorite on amino derivatives in acidic medium (157). should provide interesting insight on this reactivitv. 

Ketones are oxidized by potassium permanganate or by sodium hypochlorite (91) in aqueous solution to the corresponding acids. For example, oxidation of 5-acetylthiazole with aqueous KMnO at 70°C gives 5-thia-zolecarboxylic acid. 

Oxalic acid Furfuryl alcohol, silver, mercury, sodium chlorate, sodium chlorite, sodium hypochlorite... 

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. 

Hexanitrostilbene may be prepared by a dding a solution of TNT ia tetrahydrofuran and methanol at 5°C to aqueous sodium hypochlorite. To this mixture a 20% solution of trimethyl amine hydrochloride is added at 5—15°C. Hexanitrostilbene precipitates, and is filtered and washed with methanol and... 

The process operated by ACl is outlined in Figure 7. Bales of cotton linter are opened, cooked in dilute caustic soda, and bleached with sodium hypochlorite. The resulting highly purified ceUulose is mixed with pre-precipitated basic copper sulfate in the dissolver, and 24—28% ammonium hydroxide cooled to below 20°C is added. The mixture is agitated until dissolution is complete. If necessary, air is introduced to aUow oxidative depolymerization and hence a lowering of the dope viscosity. 

Reaction of perfluoroaLkenes and hypochlorites has been shown to be a general synthesis of perfluoroepoxides (32) (eq. 7). This appears to be the method of choice for the preparation of epoxides from internal fluoroalkenes (38). Excellent yields of HFPO from hexafluoropropylene and sodium hypochlorite using phase-transfer conditions are claimed (34). 

Several electrophiles, such as acetic anhydride, nitric acid or alternative nitrating agents, such as ammonium nitrate in trifluoroacetic anhydride (41), or sodium hypochlorite, react at N-1, which is followed by reaction at N-3 under suitable conditions. In the case of acetic anhydride, the reaction can take place exclusively at N-3 if N-1 is hindered this fact has served as a criterion for studying the stereochemistry of 5-spirohydantoin derivatives (42,43). 

The reactor effluent, containing 1—2% hydrazine, ammonia, sodium chloride, and water, is preheated and sent to the ammonia recovery system, which consists of two columns. In the first column, ammonia goes overhead under pressure and recycles to the anhydrous ammonia storage tank. In the second column, some water and final traces of ammonia are removed overhead. The bottoms from this column, consisting of water, sodium chloride, and hydrazine, are sent to an evaporating crystallizer where sodium chloride (and the slight excess of sodium hydroxide) is removed from the system as a soHd. Vapors from the crystallizer flow to the hydrate column where water is removed overhead. The bottom stream from this column is close to the hydrazine—water azeotrope composition. Standard materials of constmction may be used for handling chlorine, caustic, and sodium hypochlorite. For all surfaces in contact with hydrazine, however, the preferred material of constmction is 304 L stainless steel. 

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). 

In alkaline solutions, iodine can be oxidized to iodate by sodium hypochlorite or hypobromite, whereas chlorine passed into a solution of iodine and alkah oxidizes ah the way to periodate. 

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