Search results
Results from the WOW.Com Content Network
Arsenic acid or arsoric acid is the chemical compound with the formula H 3 AsO 4. More descriptively written as AsO(OH) 3 , this colorless acid is the arsenic analogue of phosphoric acid . Arsenate and phosphate salts behave very similarly.
The main factors are pH and the redox potential. Generally, the main forms of arsenic under oxic conditions are H 3 AsO 4, H 2 AsO − 4, HAsO 2− 4, and AsO 3− 4 at pH 2, 2–7, 7–11 and 11, respectively. Under reducing conditions, H 3 AsO 4 is predominant at pH 2–9. Oxidation and reduction affects the migration of arsenic in subsurface ...
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]
Substance Formula 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C 60 °C 70 °C 80 °C 90 °C 100 °C Barium acetate: Ba(C 2 H 3 O 2) 2: 58.8: 62: 72: 75: 78.5: 77: 75
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.
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Arsenic-arsenic bonds are very weak, and oligomeric arsenic compounds are even more liable to oxidize than their hydrogenated precursors. [6]: 318–320 The following reaction can, however, be prepared through electrochemical reduction in a zinc-sulfate cell. [6]: 473 Oxidation first forms polymeric arsinoxides, e.g.: MeAs + O → MeAsO
Arsenopyrite (IMA symbol: Apy [4]) is an iron arsenic sulfide (FeAsS). It is a hard (Mohs 5.5–6) [5] metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. [1] When dissolved in nitric acid, it releases elemental sulfur. When arsenopyrite is heated, it produces sulfur and arsenic vapor.