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It oxidises readily in air to form arsenic trioxide and water, and analogous reactions take place with sulfur and selenium instead of oxygen. [3] 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 ...
Nitric oxide (NO) reacts with reactive oxygen species to form peroxynitrite. [28] In cases of chronic arsenic exposure, the nitric oxide levels are depleted, due to the superoxide reactions. [28] The enzyme NO synthase (NOS) uses L-arginine to form nitric oxide, but this enzyme is inhibited by monomethylated arsenic (III) compounds. [28]
Despite the well known toxicity of arsenic, arsenic trioxide was used in traditional Chinese medicine, where it is known as pi-shuang (Chinese: 砒霜; pinyin: pīshuāng; lit. 'arsenic frost'). In homeopathy, it is called arsenicum album. Some discredited patent medicines, e.g., Fowler's solution, contained derivatives of arsenic oxide. [20]
Arsenic can enter groundwater due to naturally occurring arsenic at deeper levels or from mine workings. Arsenic(III) can be removed from water by a number of methods, oxidation of As III to As V for example with chlorine followed by coagulation with for example iron(III) sulfate. Other methods include ion-exchange and filtration.
It oxidises readily in air to form arsenic trioxide and water, and analogous reactions take place with sulfur and selenium instead of oxygen. [34] 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.
In its standard state arsine is a colorless, denser-than-air gas that is slightly soluble in water (2% at 20 °C) [1] and in many organic solvents as well. [citation needed] Arsine itself is odorless, [5] but it oxidizes in air and this creates a slight garlic or fish-like scent when the compound is present above 0.5 ppm. [6]
An inorganic example is the Bettendorf reaction using tin dichloride (SnCl 2) to prove the presence of arsenite ions in a concentrated HCl extract. When arsenic(III) is present, a brown coloration appears forming a dark precipitate of arsenic, according to the following simplified reaction: 2 As 3+ + 3 Sn 2+ → 2 As 0 + 3 Sn 4+
Oxyarsenides or arsenide oxides are chemical compounds formally containing the group AsO, with one arsenic and one oxygen atom. The arsenic and oxygen are not bound together as in arsenates or arsenites, instead they make a separate presence bound to the cations (metals), and could be considered as a mixed arsenide-oxide compound.