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Tantalum pentoxide, also known as tantalum(V) oxide, is the inorganic compound with the formula Ta 2 O 5. It is a white solid that is insoluble in all solvents but is attacked by strong bases and hydrofluoric acid. Ta 2 O 5 is an inert material with a high refractive index and low absorption (i.e. colourless), which makes it useful for coatings ...
Tantalum-Carbon Bond. Organotantalum chemistry is the chemistry of chemical compounds containing a carbon-to-tantalum chemical bond. A wide variety of compound have been reported, initially with cyclopentadienyl and CO ligands. Oxidation states vary from Ta(V) to Ta(-I).
Tantalum oxide is used to make special high refractive index glass for camera lenses. [80] Spherical tantalum powder, produced by atomizing molten tantalum using gas or liquid, is commonly used in additive manufacturing due to its uniform shape, excellent flowability, and high melting point. [81] [82]
The oxidation states are also maintained in articles of the elements (of course), and systematically in the table {{Infobox element/symbol-to-oxidation-state}} See also [ edit ]
Niobium forms oxides in the oxidation states +5 (Nb 2 O 5), [30] +4 (NbO 2), and the rarer oxidation state, +2 . [31] Most common is the pentoxide, also being precursor to almost all niobium compounds and alloys. [26] [32] Tantalum pentoxide (Ta 2 O 5) is the most important compound from the perspective of applications.
Oxidation states are typically represented by integers which may be positive, zero, or negative. In some cases, the average oxidation state of an element is a fraction, such as 8 / 3 for iron in magnetite Fe 3 O 4 . The highest known oxidation state is reported to be +9, displayed by iridium in the tetroxoiridium(IX) cation (IrO + 4). [1]
Tantalum pentachloride can be prepared by reacting powdered metallic tantalum with chlorine gas at between 170 and 250 °C. This reaction can also be performed using HCl at 400 °C. [4] 2 Ta + 5 Cl 2 → 2 TaCl 5 2 Ta + 10 HCl → 2 TaCl 5 + 5 H 2. It can also be prepared by a reaction between tantalum pentoxide and thionyl chloride at 240 °C
In the temperature ranges commonly used, the metal and the oxide are in a condensed state (solid or liquid), and oxygen is a gas with a much larger molar entropy. For the oxidation of each metal, the dominant contribution to the entropy change (ΔS) is the removal of 1 ⁄ 2 mol O 2, so that ΔS is negative and roughly equal for all metals.