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Molybdenum(VI) oxide is chemical compound with the formula MoO3. This compound is produced on the largest scale of any molybdenum compound. It occurs as the rare mineral molybdite. Its chief application is as an oxidation catalyst and as a raw material for the production of molybdenum metal.
Additional recommended knowledge
In the gas phase, three oxygen atoms are double bonded to the central molybdenum atom. In the solid state, anhydrous MoO3 is composed of layers of distorted MO6 octahedra in an orthorhombic crystal. The octahedra share edges and form chains which are cross-linked by oxygen atoms to form layers. The octahedra have one short molydenum-oxygen bond to a non-bridging oxygen.
Preparation and principal reactions
MoO3 is produced industrially by burning molybdenum disulfide, the chief ore of molybdenum:
The laboratory synthesis entails the acidification of aqueous solutions of sodium molybdate:
The dihydrate loses water readily to give the monohydrate. Both are bright yellow in color.
Molybdenum(VI) oxide dissolves slightly in water to give "molybdic acid." In base, it dissolves to afford the molybdate anion.
Molybdenum(VI) oxide is used to manufacture molybdenum metal, which serves as an additive to steel and corrosion-resistant alloys. The relevant conversion entails treatment of MoO3 with hydrogen at elevated temperatures:
Because of its layered structure and the ease of the Mo(VI)/Mo(V) couple, MoO3 is of interest in electrochemical devices and displays.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Molybdenum(VI)_oxide". A list of authors is available in Wikipedia.|