Sodium—continued hypochlorite

Commercial laundries have used and continue to use sodium hypochlorite as the primary bleaching agent because of its whitening and disinfectant properties. 

Hydroxy- 6-diazoandrost-5-en- l-one (96) To a stirred solution of 750 ml of methanol and 144 ml of 5 A sodium hydroxide is added 36 g (0.114 mole) of oximino ketone. Concentrated aqueous ammonia (56.6 ml, 0.850 mole) is then added followed by dropwise addition of 265 ml of cold 3 M sodium hypochlorite at a rate sufficient to maintain the temperature of the exothermic reaction mixture at 20 + 1° while cooling with an external ice bath. At temperatures below 20° appreciable amounts of a-mono- and a-dichloro ketones are obtained above 20° the chloramine decomposes before reacting with the oximino ketone. As soon as all of the sodium hypochlorite has been added, the ice bath is removed and the reaction mixture is allowed to warm to room temperature with continued stirring for 6 hr. The reaction mixture is diluted with an equal volume of water and extracted twice with... 

When such contaminated flour enters trade channels, either as such or in the form of prepared products, the finding of hair fragments is highly significant. Whether they may have come from the flour or have originated in a bakery or factory does not lessen their repugnance to the consumer. Recovered hairs are identified by means of their several characteristics. Some of the more salient are conspicuous intemodes and compound medulla of rat hairs, inconspicuous intemodes and smooth continuous medulla of cat hair, and differences discernible after treatment with 10% sodium hydroxide and after treatment with hypochlorite. 

Platinum catalysts were prepared by ion-exchange of activated charcoal. A powdered support was used for batch experiments (CECA SOS) and a granular form (Norit Rox 0.8) was employed in the continuous reactor. Oxidised sites on the surface of the support were created by treatment with aqueous sodium hypochlorite (3%) and ion-exchange of the associated protons with Pt(NH3)42+ ions was performed as described previously [13,14]. The palladium catalyst mentioned in section 3.1 was prepared by impregnation, as described in [8]. Bimetallic PtBi/C catalysts were prepared by two methods (1) bismuth was deposited onto a platinum catalyst, previously prepared by the exchange method outlined above, using the surface redox reaction ... 

Cyanide oxidation consists of a reaction with sodium hypochlorite under alkaline conditions in either a batch or continuous system. A complete system includes reactors, sensors, controls, mixers, and... 

As indicated in Table 10.12, bleaching with sodium hypochlorite is the most environmentally damaging of all bleaching processes with regard to AOX values. Consequently, despite the economical and technical benefits of this bleaching process, the use of hypochlorite will continue to decline and may even be banned in some countries. 

Various methods have been used for the reoxidation of vat leuco dyeings atmospheric skying, hypochlorite, chlorite and acidified dichromate are now rarely employed. Atmospheric oxidation can be difficult to control and thus uneven with some dyes it is also too slow, particularly for continuous methods. Sodium hypochlorite is used only for those few black dyes that tend to become dark green when oxidised with peroxide obviously hypochlorite should be avoided with the many chlorine-sensitive dyes. Similarly sodium chlorite, acidified to below pH 5 with acetic acid, can only be used with certain dyes, although with these it certainly gives rapid oxidation. Dye selectivity is also a drawback with... 

In the flask are placed 200 cc. of dioxane, 100 g. (1.02 moles) of mesityl oxide, and a solution of 4.6 moles of potassium hypochlorite in 3 1. of water (Note 1), and the stirrer is started. The mixture becomes warm immediately, and within five minutes chloroform begins to reflux. When the reaction becomes very vigorous the stirrer is stopped and the flask is cooled with running water (Note 2). The stirring is resumed as soon as feasible and is continued for three or four hours, when the temperature of the mixture will have dropped to that of the room. Sodium bisulfite (about 5 g.) is then added to react with the excess hypochlorite (Note 3). 

A 10 wt percent Calcium hypochlorite (HTH) mixture maybe substituted for Sodium Hypochlorite. Use 65 grams of decon per gram of HD and continue the test as described for Sodium Hypochlorite. 

Hypochlorite for the 10% Sodium Hydroxide solution above. Continue with 55 grams of decon per gram of GD. Agitate for one hour and allow to react for 3 hours then adjust the pH to above 10. 

There are several crucial steps in the process of recycling hypochlorite solution. First, hypochlorite is formed in the chlorine destruction where chlorine reacts with the sodium hydroxide solution. This solution is added to the brine-degassing unit. Partial conversion to chlorate and bromate takes place, which continues in the anolyte... 

The above reaction is catalyzed by copper and other trace metal impurities and can be prevented by adding a suitable complexing agent. In a modification of the Raschig process, what is known as Olin-Raschig process, liquid chlorine feed is continuously absorbed in dilute NaOH solution forming sodium hypochlorite which, similar to the Raschig process, is made to react with... 

---