Arsenic/ions/salts arsenite

Arsenic species. Arsenite and arsenate ions form the corresponding salts with Cr . Arsenous acid instantly reduces [Cr207] to Cr and, on boiling, precipitates CrAs04. 

Arsenic species. Aqueous Zn is precipitated by arsenite or arsenate ion, forming the corresponding white, gelatinous salts, readily soluble in alkalis and acids, including arsenic acids. 

Two series of compounds of arsenic are common that of arsenic(III) and arsenic(V). Arsenic(III) compounds can be derived from the amphoteric arsenic trioxide As203, which yields salts both with strong acids (e.g. arsenic(III) chloride, AsC13), and with strong bases (e.g. sodium arsenite, Na3As03). In strongly acidic solutions therefore the arsenic(III) ion As3+ is stable. In strongly basic solutions the arsenite ion, AsO is the stable one. Arsenic(V) compounds... 

Arsenic. Raman spectra78 show that in acid solutions of As406 the only detectable species is As(OH)3. In basic solutions ([OH-]/[AsUI] ratios of 3.5-15) the four pyramidal species As(OH)3, As(0H)20, As(0H)02 and As03 appear to be present. In solid salts the arsenite ion is known in the AsOf form, as well as in more complex ones. 

In natural waters, soils, and sediments, the As species of interest are the arsenate oxyanions, As(V) the arsenite oxyanions, As(III) monomethylarsonic acid, As(III) and dimethylarsinic acid, As(I). Arsenic chemistry is governed by many factors. The solubility of their salts, the complexing ability of solid and soluble ligands, the biological reactions, the pH and redox potential, and the presence of other ions are all reported to control As concentration and speciation. 

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