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Arsenate readily reacts with metals to form arsenate metal compounds. [2] [3] Arsenate is a moderate oxidizer and an electron acceptor, with an electrode potential of +0.56 V for its reduction to arsenite. [4] Due to arsenic having the same valency and similar atomic radius to phosphorus, arsenate shares similar geometry and reactivity with ...
Arsenic forms colorless, odorless, crystalline oxides As 2 O 3 ("white arsenic") and As 2 O 5 which are hygroscopic and readily soluble in water to form acidic solutions. Arsenic(V) acid is a weak acid and the salts are called arsenates, [5] the most common arsenic contamination of groundwater, and a problem that affects many people. Synthetic ...
The presence of sulfur is another factor that affects the transformation of arsenic in natural water. Arsenic can precipitate when metal sulfides form. In this way, arsenic is removed from the water and its mobility decreases. When oxygen is present, bacteria oxidize reduced sulfur to generate energy, potentially releasing bound arsenic.
In chemistry, an arsenite is a chemical compound containing an arsenic oxyanion where arsenic has oxidation state +3. Note that in fields that commonly deal with groundwater chemistry, arsenite is used generically to identify soluble As III anions. IUPAC have recommended that arsenite compounds are to be named as arsenate(III), for example ...
Arsenic (III) binding sites usually use thiol groups of cysteine residues. The catalysis involves thiolates of Cys72, Cys174, and Cys224. In an SN2 reaction, the positive charge on the SAM sulfur atom pulls the bonding electron from the carbon of the methyl group, which interacts with the arsenic lone pair to form an As−C bond, leaving SAH. [31]
Arsenate is the major arsenic form in oxidizing environments; however, in one study, bacteria from arsenic-contaminated soil at a smelter site was able to reduce As(+5) to As(+3) under anaerobic conditions at arsenic concentration as high as 75 mg/L. [3] Arsenate-respiring bacteria and Archaea have also recently been isolated from a diversity of natural environments, including freshwater ...
Arsenic is a common natural contaminant of well water and is highly carcinogenic. Iron oxide adsorption treatment for arsenic in groundwater is a commonly practiced removal process which involves the chemical treatment of arsenic species such that they adsorb onto iron oxides and create larger particles that may be filtered out of the water stream.
Arsenic forms covalent bonds with most other elements. The oxide in its preferred oxidation state (As 2 O 3, +3) is amphoteric, [n 16] as is the corresponding oxoacid in aqueous solution (H 3 AsO 3) and congener sulfide (As 2 S 3). Arsenic forms a series of anionic arsenates such as Na 3 AsO 3 and PbHAsO 4, and Zintl phases such as Na 3 As, Ca ...