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Selenium forms two oxides: selenium dioxide (SeO 2) and selenium trioxide (SeO 3). Selenium dioxide is formed by the reaction of elemental selenium with oxygen: [5] + It is a polymeric solid that forms monomeric SeO 2 molecules in the gas phase. It dissolves in water to form selenous acid, H 2 SeO 3.
Selenium tetrachloride is the inorganic compound composed with the formula SeCl 4. This compound exists as yellow to white volatile solid. This compound exists as yellow to white volatile solid. It is one of two commonly available selenium chlorides , the other example being selenium monochloride , Se 2 Cl 2 .
Selenium chloride may refer to the following chemical compounds: Selenium monochloride, Se 2 Cl 2; Selenium dichloride, SeCl 2; Selenium tetrachloride, SeCl 4
Structure of tellurium tetrachloride, tetrabromide and tetraiodide. The +2 oxidation state is exhibited by the dihalides, TeCl 2, TeBr 2 and TeI 2.The dihalides have not been obtained in pure form, [3]: 274 although they are known decomposition products of the tetrahalides in organic solvents, and the derived tetrahalotellurates are well-characterized:
At higher pH, selenide forms. Solutions of hydrogen selenide and selenide are oxidized by air to give elemental selenium: 2 SeH − + O 2 → 2 Se + 2 OH −. Most elements form selenides. They sometimes have salt-like properties, e.g. sodium selenide, but most exhibit covalent bonding, e.g. molybdenum diselenide. Their properties are diverse ...
The original synthesis involved the redistribution reaction of selenium dioxide and selenium tetrachloride. Pure selenium oxydichloride autoionizes to a dimer: [4] SeOCl 2 ↔ (SeO) 2 Cl + 3 + Cl −. The SeOCl 2 is generally a labile Lewis acid and solutions of sulfur trioxide in SeOCl 2 likely form [SeOCl] + [SO 3 Cl] − the same way. [5]
A metal ion in aqueous solution or aqua ion is a cation, dissolved in water, of chemical formula [M(H 2 O) n] z+.The solvation number, n, determined by a variety of experimental methods is 4 for Li + and Be 2+ and 6 for most elements in periods 3 and 4 of the periodic table.
Both ionic and covalent iodides are known for metals in oxidation state +3 (e.g. scandium iodide is mostly ionic, but aluminium iodide is not). Ionic iodides MI n tend to have the lowest melting and boiling points among the halides MX n of the same element, because the electrostatic forces of attraction between the cations and anions are ...