arseneto

Arseneto is a term used in some languages to describe salts and esters of arsenic acid that contain the arsenate group AsO4^3−. In English, the standard term is arsenate; arseneto is encountered as a vernacular or older form in certain regional contexts. Arsenates arise when arsenic is in the +5 oxidation state in oxy-acid chemistry. The conjugate base forms of arsenic acid include dihydrogen arsenate (H2AsO4−), hydrogen arsenate (HAsO4^2−), and the tetra- oxyanion arsenate (AsO4^3−), which combine with metals or form esters with organic groups.

Chemically, arsenates are tetrahedral oxyanions that participate in acid–base equilibria depending on pH. They form a wide class of salts, such as calcium arsenate Ca3(AsO4)2, sodium arsenate Na3AsO4, and lead arsenate Pb3(AsO4)2. Arsenate esters, including alkyl arsenates, are also known. The pH-dependent speciation means different protonation states can predominate in solutions from strongly acidic to highly basic conditions.

Occurrence and minerals: arsenate groups occur naturally in a range of minerals and secondary deposits. Common arsenate-bearing minerals include scorodite FeAsO4·2H2O and mimetite Pb5(AsO4)3Cl, among others. Arsenates are often associated with other arsenic-bearing minerals and may be important indicators in environmental and ore-deposit contexts.

Uses and history: arsenates have historically been used as pesticides (e.g., calcium arsenate and lead arsenate) and in wood preservation. Modern use is restricted due to toxicity and environmental concerns; regulatory controls limit exposure and manage residues in soil and water.

Safety and environmental impact: arsenates are toxic and can disrupt phosphate metabolism in living organisms. Chronic exposure to arsenic compounds, including arsenates, is a public health concern, prompting monitoring and remediation in contaminated ecosystems.