Divanadium pentoxide

Ternary alkali metal vanadium oxide bronzes are well known, including 7-LiVjOj. It was recognized that some other composition or structure was formed from the combination of lithium and VjOj at room temperature through electrochemical or butyllithium reactions. It is possible to prepare the low-temperature b-LiV Os with butyllithium, although irreversible overreduction is difficult to avoid. The use of Lil as reductant avoids any overreduction.  

The UV2OS formed in this way is dark blue and is stable in air for moderate lengths of time. Long-term storage in a desiccator is satisfactory. The compound is orthorhombic with a = 11.272 k, b = 4.971 A, and c = 3.389 A. A reversible first-order structural transformation occurs at 125° to e-LiV O, which is also orthorhombic with a = 11.335 k, b = 4.683 A, and c = 3.589 A. Above 300° the structure changes irreversibly to that of the thermally stable y-UV2O5. 

Ternary alkali-metal vanadium oxide bronzes are well known, including y-LiV205. It was recognized that some other composition or structure was 

ReOj -I- 2BuLi -+ LijReOj -i- octane 2Li2ReOj -I- 2EtOH 2LiRe03 -f 2LiOEt -I- H2 ReOj + excess Lil - Lig 2Re03 + Lil + I2 

Rhenium trioxide has one of the simplest extended structures. Octahedral (ReOg) units share oxygen atoms between units such the Re—O—Re bonds are linear. The symmetry is cubic, and each cell contains one Re and one 

Three phases have been identified in the Li ReOs system. For x 0.35 the structure remains cubic. A line phase at x = 1.0 is rhombohedral, as is a 

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The catalyst used is divanadium pentoxide, V2C>5, at a temperature of450°C to 600°C. Sulfur trioxide is an acidic oxide that reacts with water to form sulfuric acid. 

Divanadium pentoxide is reduced very violently by lithium at 394-768 C. With calcium containing sulphur in the form of impurities, in the presence of water traces, a violent combustion is observed. 

Usually the nitric acid/amine interaction is more dangerous when impurities that can play a catalytic role are present. This goes for metal oxides such as copper oxides, iron (III) oxide and divanadium pentoxide. Salts such as sodium or ammonium metavanadates, iron trichloride, alkaline chromates and dichromates, cyanoferrates and alkaline or nitrosopentacyanoferrates can also act as catalysts. 

Synonyms Vanadic anhydride divanadium pentoxide vanadium oxide vanadic acid... 

Vanadium can form several different compounds with oxygen, including V205, V02, and V203. Determine the number of moles of oxygen that are needed to react with 0.56 mol of vanadium to form divanadium pentoxide, V205. 

SYNONYMS divanadium pentoxide, vanadic anhydride, vanadium oxide, vanadium pentoxide, vanadium pentoxide. 

Synonyms/Trade Names Divanadium pentoxide dust. Vanadic anhydride dust. Vanadium oxide dust. Vanadium pentaoxide dust. Other synonyms vary depending upon the specific vanadium compound. 

The equilibrium constant for this reaction is 1.7 X 10 , which indicates that for all practical purposes the reaction should go almost completely to products. Yet when sulfur is burned in air or oxygen, it forms predominantly SO2 and very little SO3. Oxidation of SO2 to SO3 is simply too slow to give a significant amount of product. However, the rate of the reaction is appreciable in the presence of a platinum or divanadium pentoxide catalyst. The oxidation of SO2 in the presence of a catalyst is the main step in the contact process for the industrial production of sulfuric acid, H2SO4. Sulfur trioxide reacts with water to form sulfuric acid. (In the industrial process, SO3 is dissolved in concentrated H2SO4, which is then diluted.) ... 

This reaction is the crucial step in the usual process for making sulfuric acid, H,SO, (page 444). The reaction is extremely slow under ordinary conditions, but proceeds quite rapidly above 500 C in the presence of a catalyst (page 420), such as divanadium pentoxide (V,0,) or platinum. Table 11.1 shows data from experiments (Max Bodenstein,... 

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