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Water selenides

Birss VI, Wright GA (1981) The kinetics of the anodic formation and reduction of phase silver sulfide films on silver in aqueous sulfide solutions. Electrochim Acta 26 1809-1817 Petrov GV, Belen ku AM (2005) Interactions in the silver selenide-water system. Russ J Appl Chem 78 53-56... [Pg.146]

This magnesium-dependent enzyme [EC 2.7.9.3], also known as selenide,water dikinase and selenium donor protein, catalyzes the reaction of ATP with selenide and water to produce AMP, selenophosphate, and orthophosphate. [Pg.633]

Guanajuatite, see Bismuth selenide Gypsum, see Calcium sulfate 2-water... [Pg.274]

Nantokite, see Copper(I) chloride Natron, see Sodium carbonate Naumannite, see Silver selenide Neutral verdigris, see Copper(H) acetate Nitre (niter), see Potassium nitrate Nitric oxide, see Nitrogen(II) oxide Nitrobarite, see Barium nitrate Nitromagnesite, see Magnesium nitrate 6-water Nitroprusside, see Sodium pentacyanonitrosylfer-rate(II) 2-water... [Pg.274]

Wet chlorination is performed by sparging slimes slurried either in water or hydrochloric acid using chlorine gas, or other oxidants such as sodium chlorate or hydrogen peroxide which Hberate chlorine from hydrochloric acid, at about 100°C. Under these conditions, selenium and selenides rapidly oxidize and dissolve. [Pg.330]

Bina Selenides. Most biaary selenides are formed by beating selenium ia the presence of the element, reduction of selenites or selenates with carbon or hydrogen, and double decomposition of heavy-metal salts ia aqueous solution or suspension with a soluble selenide salt, eg, Na2Se or (NH 2S [66455-76-3]. Atmospheric oxygen oxidizes the selenides more rapidly than the corresponding sulfides and more slowly than the teUurides. Selenides of the alkah, alkaline-earth metals, and lanthanum elements are water soluble and readily hydrolyzed. Heavy-metal selenides are iasoluble ia water. Polyselenides form when selenium reacts with alkah metals dissolved ia hquid ammonia. Metal (M) hydrogen selenides of the M HSe type are known. Some heavy-metal selenides show important and useful electric, photoelectric, photo-optical, and semiconductor properties. Ferroselenium and nickel selenide are made by sintering a mixture of selenium and metal powder. [Pg.332]

Contact with elemental selenium does not injure the skin. Selenium dioxide, however, upon contact with water, sweat, or tears, forms selenous acid, a severe skin irritant. Selenium oxyhaHdes are extremely vesicant and cause bums when in contact with human skin (91,92). Hydrogen selenide affects the mucous membranes of the upper respiratory tract and the eyes (93). [Pg.335]

Sodium selenite has also been incorporated into styrene—butadiene mbber and used in a pellet form which results in the slow release of selenium into water. These pellets have been placed in lakes in Sweden which have fish contaminated with mercury owing to high levels of that element in the water. The selenium released by the pellets reacts with mercury to form insoluble, heavy mercury selenide which setties to the lake bottom and removes mercury from the ecosystem (126). [Pg.338]

Most selenides and tellurides are decomposed by water or dilute acid to form H2Se or H2Te but the yields, particularly of the latter, are poor. [Pg.766]

A process for the gravimetric determination of mixtures of selenium and tellurium is also described. Selenium and tellurium occur in practice either as the impure elements or as selenides or tellurides. They may be brought into solution by mixing intimately with 2 parts of sodium carbonate and 1 part of potassium nitrate in a nickel crucible, covering with a layer of the mixture, and then heating gradually to fusion. The cold melt is extracted with water, and filtered. The elements are then determined in the filtrate. [Pg.466]

A) Diphenylselenium Dichloride.—One hundred twenty-five grams (0.53 mole) of diphenyl selenide (p. 27) is added in portions to 250 cc. (4 moles) of nitric acid (sp. gr. 1.42) in a 1.5-I. beaker. Hydrochloric acid (sp. gr. 1.18) is then added until precipitation is complete. About 170 cc. (2 moles) of acid is required. The mixture is then diluted with 500 cc. of water, and the yellow precipitate is separated by filtration and air-dried. The crude product is purified by extracting with 500 cc. of boiling benzene. The crystals which separate on cooling are collected on a filter and the filtrate used for a further extraction. Three such treatments are necessary for a complete crystallization. The yield of yellow needles, decomposing at 187-188°, is 137-141 g. (85-87 per cent of the theoretical amount). [Pg.30]

In the case of selenium compounds in the presence of water, only gold selenide, AuSe, is formed (309). [Pg.343]

The synthetic approach is very simple and does not require any special set up. In a typical room temperature reaction, 1.0 mL aqueous solution of cadmium chloride was added to 20 mL aqueous solution of soluble starch in a 50 mL one-necked round-bottom flask with constant stirring at room temperature. The pH of the solution was adjusted from 6 to 11 using 0.1 M ammonia solution. This was followed by a slow addition of 1.0 mL colourless selenide ion stock solution. The mixture was further stirred for 2 h and aged for 18 h. The resultant solution was filtered and extracted with acetone to obtain a red precipitate of CdSe nanoaprticles. The precipitate was washed several times and dried at room temperature to give a material which readily dispersed in water. The same procedure was repeated for the synthesis of PVA and PVP - capped CdSe nanoparticles by replacing the starch solution with the PVA and PVP polymers while the synthesis of elongated nanoparticles was achieved by changing the Cd Se precursor ratio from 1 1 to 1 2. The synthesis of polymer capped ZnSe nanoparticles also follows the same procedure except that ZnCb solution was used instead of CdCb solution. [Pg.167]

Oluwafemi, O. S., Revaprasadu, N. and Ramirez, A. J. (2008). A Novel One-Pot route for the Synthesis of Water-Soluble Cadmium Selenide Nanoparticles. /. Cryst. Growth, 310, 3230-3234. [Pg.183]

A 30% solution of hydrogen peroxide in water was purchased from Mallinckrodt Chemical Works. The reaction requires 2 molar equivalents of hydrogen peroxide, the first to oxidize the selenide to the selenoxide and the second to oxidize the elimination product, benzeneselenenic acid, to benzeneseleninic acid. The submitters recommend that the hydrogen peroxide solution be taken from a recently opened bottle, or titrated to verify its concentration. [Pg.167]

Fig. 2.3 Potential-pH equilibrium diagram for the system selenium-water, at 25 °C (gaseous hydrogen selenide is designated in italic letters) (Reproduced from [3], Copyright NACE International 2010)... Fig. 2.3 Potential-pH equilibrium diagram for the system selenium-water, at 25 °C (gaseous hydrogen selenide is designated in italic letters) (Reproduced from [3], Copyright NACE International 2010)...
Selenium is stable in water and in aqueous solutions over the entire pH interval in the absence of any oxidizing or reducing agent. Selenium can be electrochemically reduced to hydrogen selenide or to selenides that are unstable in water and aqueous solutions. It can be oxidized to selenous acid or selenites and further (electrolyti-cally) to perselenic acid (H2Se20s). Selenic and selenous acids and their salts are stable in water. The selenides, selenites, and selenates of metals other than the alkali metals are generally insoluble. [Pg.69]

The selenium species that are drawing most attention are Se(IV) and Se(VI) in water and sediments, and the biomethylated products (dimethylselenide and dimethyldi-selenide) that are spread into the environment (Camara et al. 1995). Se-species in food (including Se-cysteine and other species in yeast) are in the limelight (Crews 1998) because of their beneficial effect on human health and their increasing use as nutraceuticals. [Pg.81]


See other pages where Water selenides is mentioned: [Pg.101]    [Pg.208]    [Pg.235]    [Pg.164]    [Pg.379]    [Pg.179]    [Pg.327]    [Pg.327]    [Pg.328]    [Pg.332]    [Pg.202]    [Pg.217]    [Pg.24]    [Pg.24]    [Pg.766]    [Pg.767]    [Pg.257]    [Pg.451]    [Pg.251]    [Pg.379]    [Pg.165]    [Pg.166]    [Pg.169]    [Pg.155]    [Pg.112]    [Pg.4]    [Pg.6]    [Pg.12]    [Pg.241]    [Pg.316]   
See also in sourсe #XX -- [ Pg.3 , Pg.46 ]




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