Solubility of molybdenum

Ivan, M. and D.M. Veira. 1985. Effects of copper sulfate supplement on growth, tissue concentration, and ruminal solubilities of molybdenum and copper in sheep fed low and high molybdenum diets. Jour. Dairy Sci. 68 891-896. 

There is also evidence that the beneficial effect of molybdenum is to interfere with pit propagation. If the mechanism is active at the initiation of localized breakdown of the passive film, then, effectively, pitting will not occur. Based on the low solubility of molybdenum chloride, Mo03, and polymolybdates in acid solutions, one mechanism proposes that molybdenum enhances the formation of salt films of these species within the pit. This can decrease the IR potential drop to the pit... 

Jones, L. H. P. (1957). The solubility of molybdenum in simplified systems and aqueous soil suspensions. J. Soil Sci. 8 313-27. 

As is seen, in the NaPOs-NaCl system similar to Mo(V) and W(V) polyhedra of the same composition and structure are formed that predetermines possible similarity of their electrochemical behavior. Indeed, in the system studied the values of tungsten and molybdenum reduction potentials were proved to be almost identical and more positive as compared to the phosphorus reduction potential (Fig.4). In addition, solubility of molybdenum and tungsten trioxides was found to be fairly high and the binary system metaphosphate-sodium chloride rather low-melting. 

Condition/ beta in the annealed condition than Ti-6A1-4V be-Microstructure cause of the much lower solubility of molybdenum... 

The dichloride of molybdenum(II) [13478-17-6] M0CI2, contains Mo CF g core units (Fig. 6c) having chloride bridges in its soHd-state stmcture. Similar or identical hexanuclear units are known in soluble species such as Mo3Ch 24 other derivatives containing the Mo CF g core. These compounds have been under investigation because of their photochemical and photoluminescent activity (see Photochemical technology) (36,37). The hexanuclear... 

Coatings, Paints, and Pigments. Various slightly soluble molybdates, such as those of zinc, calcium, and strontium, provide long-term corrosion control as undercoatings on ferrous metals (90—92). The mechanism of action presumably involves the slow release of molybdate ion, which forms an insoluble ferric molybdate protective layer. This layer is insoluble in neutral or basic solution. A primary impetus for the use of molybdenum, generally in place of chromium, is the lower toxicity of the molybdenum compound. 

Molybdates yield sparingly soluble orange-yellow molybdyl oxinate with oxine solution the pH of the solution should be between the limits 3.3-7.6. The complex differs from other oxinates in being insoluble in organic solvents and in many concentrated inorganic acids. The freshly precipitated compound dissolves only in concentrated sulphuric acid and in hot solutions of caustic alkalis. This determination is of particular interest, as it allows a complete separation of molybdenum from rhenium. 

Toluene-3,4-dithiol, usually called dithioP, yields a slightly soluble, dark-green complex, (CH3.C6H3.S2)3Mo(VI), with molybdenum(VI) in a mineral acid medium, which can be extracted by organic solvents. The resulting green solution is used for the colorimetric determination of molybdenum. 

It has been found that when molybdenum carbide (Mo2C) is used as the soluble anode, a loose carbon crust forms on the surface of the pellets as the dissolution of molybdenum progresses. X-ray diffraction analysis of the spent anode has indicated a predominance of the Mo2C phase. This suggests that the anodic reaction proceeds as... 

Various other techniques have been used to determine molybdenum, including adsorption voltammetry [510], electron-paramagnetic resonance spectrometry [512], and neutron activation analysis [513,514]. EPR spectrometry is carried out on the isoamyl alcohol soluble Mo(SCN)s complex and is capable of detecting 0.46 mg/1 molybdenum in seawater. Neutron activation is carried out on the /J-naphlhoin oxime [514] complex and the pyrrolidone dithiocar-bamate and diethyldithiocarbamate complex [513]. The neutron activation analysis method [514] was capable of determining down to 0.32 xg/l of molybdenum in seawater. 

Figure 5.3. The high-temperature region of the Mo-H system is shown. In this temperature range the negligible solubility of hydrogen in solid and liquid molybdenum can be noticed.

Direct comparisons of the stability constants for formation of the dmpp complexes of molybdenum(VI) with those for uranium(VI) are not possible. The mono-ligand complexes have different stoichiometries, MoOaldmpp) versus U02(dmpp), while although log P2 is available for Mo02(dmpp)2 (175) the value of 40.2 refers to formation from Mo04 rather than from MoOg laq), and U02(dmpp)2 is too sparingly soluble for its formation constant to be determined (231). 

Workers at a molybdenum-roasting plant with time-weighted average (TWA) exposures of approximately 9.5mgMo/m to soluble dusts had increased plasma and urine levels of molybdenum the only adverse biochemical findings were large elevations in serum ceruloplasmin levels and some increase in serum uric acid levels. ... 

Bulk techniques still have a place in the search for presolar components. Although they cannot identify the presolar grain directly, they can measure anomalous isotopic compositions, which can then be used as a tracer for separation procedures to identify the carrier. There are several isotopically anomalous components whose carriers have not been identified. For example, an anomalous chromium component enriched in 54Cr appears in acid residues of the most primitive chondrites. The carrier is soluble in hydrochloric acid and goes with the colloidal fraction of the residue, which means it is likely to be submicron in size (Podosck el al., 1997). Measurements of molybdenum and ruthenium in bulk primitive meteorites and leachates from primitive chondrites show isotopic anomalies that can be attributed to the -process on the one hand and to the r- and /7-processes on the other. The s-process anomalies in molybdenum and ruthenium correlate with one another, while the r- and /7-process anomalies do not. The amounts of -process molybdenum and ruthenium are consistent with their being carried in presolar silicon carbide, but they are released from bulk samples with treatments that should not dissolve that mineral. Thus, additional carriers of s-, r-, and/ -process elements are suggested (Dauphas et al., 2002). 

The suspension polymerization of norbom-5-ene-2,3-dicarbox-ylic anhydride in dichloromethane using a molybdenum-based initiator results in living, linear polymer chains with the active initiator at the polymer chain end. The solubility of the poly(norbom-5-ene-2,3-dicarboxylic anhydride) is dependent on the chain length. 

The absence of evidence for a ligating hydrogen suggests the formulation of the product as [Mo(dppe)2] or its dimer. The relatively low solubility of the complex has thus far prevented molecular weight measurements. An ortho-metallated derivative, which might be expected, would be expected to show evidence for a molybdenum-hydride bond. The overall photochemical reaction that is consistent with this formulation and with the quantity of hydrogen released is given in Reaction 12. 

The use of highly dispersed catalysts from soluble salts of molybdenum is another approach to the reduction of catalyst amount because of their excellent activity despite their higher price. Recently, metal carbonyl compounds, such as Fe(CO)5, Ru3(CO)i2, and Mo(CO)6 have been investigated as metal cluster catalysts. Preparation involved their deposition and decomposition on catalyst support surfaces (71-73). 

In a definitive series of experimental investigations H. N. Wilson showed that the quinolinium salt, (C isNJ fPCV I2M0O3]3- was anhydrous, contained exactly 12 moles of molybdenum trioxide per mole of phosphate, that the precipitate had a negligible solubility and could be dried to constant weight in two hours at 105 °C. This precipitate also lent itself to a precise alkalimetric titration. In the presence of citric acid interference by silica was inhibited so that the method was admirably suitable for the analysis of basic slags or fertilizers.34... 

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