Sodium metarsenite

Cobalt Pyroarsenite, Co2As305, is obtained when a dilute solution of cobaltous nitrate is precipitated with sodium metarsenite,6... 

Tin Arsenites.—Stannous Orthoarsenite, Sn3(As03)2.H20, was obtained by Stavenhagen 3 by adding a solution of arsenious oxide to a solution containing potassium ehlorostannite and potassium chloride. It may also be obtained 4 by the action of sodium metarsenite or potassium tetrarsenite on a solution of stannous chloride. It is a white amorphous powder, sparingly soluble in water, but readily dissolved by dilute acids and alkalis with separation of metallic arsenic. It is also soluble in excess of arsenious acid. 

Uranyl Metarsenite, U02(As02)2, is formed as a yellow precipitate when a solution of sodium metarsenite 2 or of potassium tetrarsenite 3 is added to one of uranyl nitrate. It is insoluble in ammonia, but dissolves readily in acids. On heating, it darkens in colour and decomposes. 

Zinc Orthoarsenite, Zn3(As03)2, is obtained7 as a white crystalline precipitate when aqueous arsenious acid is added to a solution of zinc sulphate containing ammonia and ammonium chloride precipitation occurs in the cold, an aggregate of crystalline needles being rapidly formed. A similar precipitate is thrown down by potassium orthoarsenite from a solution of zinc chloride in 50 per cent, alcohol,8 or from a solution of zinc sulphate by potassium tetrarsenite9 or sodium metarsenite.10 Zinc orthoarsenite dissolves readily in acids. It decomposes when heated. 

Sodium, Dioxydithioarsenate, Na3As02S2, may be obtained by the action of aqueous sodium sulphide on arsenious oxide,2 or of the disulphide on sodium metarsenite—3... 

Figure 12.6 206Pb/207Pb versus 208Pb/207Pb plot of lead arsenate ( 1), sodium metarsenite... 

Although the predominant source of arsenic and metals to most soils and sediments in New England is sulfide-rich rock, the extensive application of arsenical pesticides and herbicides (lead arsenate, calcium arsenate, and sodium arsenate, and others) on apple, blueberry, and potato fields may have been a possible anthropogenic source of arsenic and lead. The main objective of this study was to determine the lead isotopic compositions of commonly used pesticides, such as lead arsenate, sodium metarsenite, and calcium arsenate, in order to assist in future isotopic comparisons and to better characterize this anthropogenic source of Pb. The pesticides plot along a linear trend in isotope diagrams, for example, in values of... 

Cobalt Arsenites.—When a dilute solution of cobalt nitrate is precipitated with sodium metarsenite, a violet-blue voluminous deposit of cobalt pyro-arsenite, Co2As205 or 2CoO.As203, is obtained.3... 

Zinc Metarsenite, Zn(As02)2, is obtained as a granular white powder by dissolving arsenious acid in sodium hydroxide solution, making just acid to phenolphthalein with dilute sulphuric acid and adding hot zinc sulphate solution.11 It is also formed when aqueous arsenious acid is mixed with a solution of zinc acetate in dilute acetic acid. 

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