Sodium arsenates

Basic copper ethanoate arsenates(iii) prepared from verdigris (or other basic copper salt), sodium arsenate(m) and ethanoic acid. Used in insecticides for spraying fruit trees. Readily decomposed to soluble arsenic compounds so use is very restricted. 

If the temperature falls below 40°, a precipitate of sodium arsenate will gradiially separate and this will tend to produce an emulsion of the methylene iodide, thus rendering filtration and separation difficult. 

The niter and fresh caustic soda, required to maintain the fluidity of the salt bath in the reactor chamber, are added gradually. When the color of the saturated salts turns from a dark gray to white, the impurity metals are at their highest state of oxidation, and the lead content of the spent salts is very low. In a modification, the arsenic and tin are selectively removed as sodium arsenate and sodium stannate, followed by the removal of antimony as sodium antimonate. 

Wet Process. The sodium arsenate and stannate slag are treated by a leach and precipitation process to produce calcium arsenate, calcium stannate, and a sodium hydroxide solution for recycle. The sodium antimonate filtercake containing selenium, tellurium, and indium is treated in a special metals refinery to recover indium and tellurium. 

Plants can also be pests that need to be controlled, particulady noxious weeds infesting food crops. Prior to 1900, inorganic compounds such as sulfuric acid, copper nitrate, sodium nitrate, ammonium sulfate, and potassium salts were used to selectively control mustards and other broadleaved weeds in cereal grains. By the early 1900s, Kainite and calcium cyanamid were also used in monocotyledenous crops, as well as iron sulfate, copper sulfate, and sodium arsenate. Prom 1915 to 1925, acid arsenical sprays, carbon bisulfate, sodium chlorate, and others were introduced for weed control use. Total or nonselective herbicides kill all vegetation, whereas selective compounds control weeds without adversely affecting the growth of the crop (see Herbicides). 

Arsenates are oxidizing agents and are reduced by concentrated hydrochloric acid or sulfur dioxide. Treatment of a solution of orthoarsenate with silver nitrate in neutral solution results in the formation of a chocolate-brown precipitate of silver orthoarsenate, Ag AsO, which may be used as a test to distinguish arsenates from phosphates. With hydrofluoric acid, orthoarsenate solutions yield hexafluoroarsenates, eg, potassium hexafluoroarsenate [17029-22-0] (KAsFg)2 H2O. Arsenates of calcium or lead are used as insecticides sodium arsenate is used in printing inks and as a mordant. 

Sodium antimonyl tartrate [34521-09-0] M 308.8. Crystd from water. Sodium arsenate (7H2O)... 

SODIUM AMMONIUM VANADATE SODIUM ARSAHILATE SODIUM ARSENATE SODIUM ARSENITE... 

Chemical Designations - Synonyms Disodium arsenate heptahydrate Sodium arsenate, dibasic Chemical Formula Na2Has04 7Hi0. 

Fig. 3.2.3 Absorption spectra of the fluorescent compound F in 50% ethanol (solid line) and the protein P in 20 mM sodium arsenate, pH 6.5, containing 0.5 M KC1 (dashed line). Both F and P were obtained from Meganyctiphanes norvegica. From Shimomura, 1995a, with permission from John Wiley Sons Ltd.

Arsenic trichloride Gallium arsenide Potassium arsenate Arsine Arsenic add Sodium arsenate Sodium arsenite CaicKjm arsenate Arsenic trioxide Arsenic pwtoxide Arsenic bisulphide Arsenic pentasulphide Arsenic hemiselenide... 

Arsenic trioxide, Sodium arsenate, Sodium hydroxide... 

For arsenic (added as sodium arsenate) and selenium (added as sodium selenite), losses were insignificant in all the container materials considered, irrespective of matrix composition. 

Silvisar-510 (mixture of cacodylic acid and triethanolamine cacodylate) MALLARD, Anasplatyrhynchos Sodium arsenate... 

Single oral dose Arsenous oxide Tetramethylarsonium iodide Dimethylarsinic acid Dimethylarsonic acid Arsenocholine Trimethylarsinoxide Arsenobetaine Sodium arsenate... 

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