Copper, arsenite carbonates

Copper compounds are used routinely and widely to control freshwater snails that serve as intermediate vectors of schistosomiasis and other diseases that afflict humans (Hasler 1949 NAS 1977 Rowe and Prince 1983 Winger etal. 1984 Al-Sabri etal. 1993). These compounds include copper sulfate, copper pentachlorophenate, copper carbonate, copper-tartaric acid, Paris green (copper arsenite-acetate), copper oxide, copper chloride, copper acetyl acetonate, copper dimethyl dithiocar-bamate, copper ricinoleate, and copper rosinate (Cheng 1979). Also, many species of oyster enemies are controlled by copper sulfate dips. All tested species of marine gastropods, tunicates, echinoderms, and crabs that had been dipped for 5 seconds in a saturated solution of copper sulfate died if held in air for as little as a few seconds to 8 h mussels, however, were resistant (MacKenzie 1961). 

Like zinc, copper and its compounds have been used since ancient times, with copper dust, acetate, sulfate and carbonate reported in Egyptian and Hindu prescriptions, and also used by Hippocrates and Galen. Copper arsenite was used in 1892 for anemia and debility. Copper sulfate was recommended to strengthen man, to stimulate the heart and blood vessels, to increase deposition of fat and to treat anemia. The adult requirement is 1.25 mg Cud-1, about one third of which is absorbed. TPN should be supplemented with 0.5—1.5 mg d-1 (adults) and 20 gg (kg weight)-1 d-1 (children). 

The carbonates, sulphates, and borates are decomposed. The sulphides of the alkalies and alkaline earths are decomposed while the sulphides of arsenic, antimony, molybdenum, zinc, cadmium, tin, iron, lead, copper, mercury, and palladium are not attacked. Cobalt sulphate is not attacked, while the sulphates of the alkalies and alkaline earths are attacked and dissolved. Alkali tungstates, ammonium arsenite and arsenate, copper arsenite, ammonium magnesium arsenate, ammonium molybdate and vanadate, potassium cyanide and ferrocyanide are decomposed. Paraffin is not attacked shellac, gum arabic, gum tragacanth, copal, etc., are decomposed. Celluloid is slowly attacked. Silk paper, gun cotton, gelatin, parchment are dissolved. M. Meslans 22 has studied the esterification of alcohol by hydrofluoric acid. 

Rose (1916) describes this under the German term Wiesengriin, meadow green, as a mixture of copper arsenite, copper phosphate and copper carbonate. 

Arylarsonic acids are most readily prepared by the Bart Reaction, in which a diazonium salt in aqueous solution is run into a solution of sodium arsenite in an excess of sodium carbonate. The addition of copper sulphate to the +. ... 

Concurrently with the preparation of the phenyldiazonium chloride solution, prepare a cold suspension of sodium arsenite. Place 250 ml. of water in a 3-htre round-bottomed flask equipped with a mechanical stirrer. Heat the water to boding, add 125 g. of anhydrous sodium carbonate, and, as soon as the carbonate has dissolved, introduce 62 5 g. of pure arsenious oxide and 3 g. of crystallised copper sulphate with stirring. When all the solids have dissolved, cool the solution with stirring under a stream of tap water until the temperature has fallen to 15°. 

The oxidation of arsenites by oxygen in the presence of sodium hydroxide is affected by the presence of other types of catalysts (see p. 175). Thus in the presence of copper sulphate and with less alkali than corresponds with Na3As03, the velocity of oxidation is very small, but with an increased amount of sodium hydroxide present, copper hydroxide or oxide is formed and the action is accelerated, and indeed copper oxide itself may be used as catalyst.2 With an excess of sodium hydroxide and a suitable quantity of copper oxide, normal sodium arsenite may be completely oxidised to arsenate in a few hours. Similarly the presence of an excess of sodium carbonate facilitates oxidation.3... 

After an extensive study of the adsorption of arsenious oxide by metallic hydroxides,3 Sen concluded that this type of adsorption resembles that of cations by manganese dioxide, and that the chemical affinity between the adsorbent and the substance adsorbed plays an important part, thus differing from adsorption by charcoal. It has been observed that soils having a high absorption capacity for bases also absorb the arsenite ion from solutions of 0-001 to 0-01X concentration.4 The absorption increases with time, without reaching an end-point, and the process follows the normal adsorption equation C1=kC1Jn. The addition of ferric oxide or calcium carbonate to the soil considerably increases the capacity for absorption, but such salts as calcium sulphate or copper sulphate have no effect. 

Many samples have redox potentials such fiiat fiiey can be oxidized by iodine. Therefore, file iodine in file titrant may be consumed by readily oxidizable samples fiiat will give a false high value for file water content. Some common substances fiiat can be oxidized by iodine are ascorbic acid, arsenite (As02 ), arsenate (As04 ), boric acid, tetraborate (3407 ), carbonate (COs ), disulfite (8205 ), iron(ll) salts, hydrazine derivatives, hydroxides (OH ), bicarbonates (HCOs"), copper(l) salts, mercaptans (RSH), nitrite (N02 ), some metal oxides, peroxides, selenite (SeOs "), silanols (RsSiOH), sulfite (SOs ), tellurite (TeOs ), fiiiosulfate (8203 ), and tin(ll) salts. For situations such as fiiese where file material under analysis reacts wifii iodine, an oven can be used to liberate fiie moisture from file sample, which is fiieii carried into file reaction vessel and titrated wifiiout interference. 

A solution of 172 g. (1.0 mole) of p-bromoaniline, 300 ml. of hydrochloric acid, and 400 ml. of water is poured on to 800 g. of crushed ice. The resulting mixture is diazotized by the dropwise addition of a solution of 70 g. (1.0 mole) of sodium nitrite in 200 ml. of water, the temperature of the reaction mixture being kept below 5". A mixture of 5 g. of copper sulfate, 50 ml. of water, and 10 ml. of concentrated aqueous ammonia solution is added to a solution of 210 g. of sodium arsenite and 250 g. of sodium carbonate in 2 1. of water, and the mixture is cooled to 15°. The solution of the diazotized amine is added to the arsenite solution with stirring over a period of 1 hour. The reaction mixture is stirred for 2 hours, allowed to stand for 12 hours, and filtered. The filtrate is acidified with concentrated hydrochloric acid to Congo red, and the precipitated p-bromophenylarsonic acid is filtered off. The yield is 193 g. 

The principal ore of arsenic (5 x 10 % of earth s crust) is arsenical pyrites, FeAsS, but the element occurs commonly with nickel, copper and tin As40g is recovered from flue-dusts collected during the extraction of these metals. Sublimation in the presence of galena, which prevents the formation of arsenites, purifies the oxide this is reduced to arsenic with carbon in a cast iron retort. The element itself has few uses about 0.5% added to lead increases the surface tension of the molten metal and allows spherical lead-shot to be produced. The principal commercial form is the so-called white arsenic, As Og. Arsenic compounds are used mainly for their toxicity arsenical insecticides have been much used. 

Catalysts having a very acid nature such as metaphosphoric acid, arsenious acid, boric acid, or salts of these acids have been proposed. The addition of copper as such or as the formate serves to promote the reaction.190 Reaction chambers extremely resistant to corrosion must be tised. Catalysts such as zinc arsenite. or zinc or chromium metaphosphatc having a highly acidic nature are claimed to be effective in the formation of organic acids from carbon monoxide and alcohols at temperatures of about 300° C. and a pressure of 200 atmospheres. Even with such acidic catalysts considerable quantities of esters are stated to be formed.101... 

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