Cobalt vapor pressure

Clausius-Clapeyron equation An equation expressing the temperature dependence of vapor pressure ln(P2/Pi) = AHvapCl/Tj - 1/T2)/R, 230,303-305 Claussen, Walter, 66 Cobalt, 410-411 Cobalt (II) chloride, 66 Coefficient A number preceding a formula in a chemical equation, 61 Coefficient rule Rule which states that when the coefficients of a chemical equation are multiplied by a number n, the equilibrium constant is raised to the nth power, 327... 

Vapor pressure measurements of cobalt hydrocarbonyl are difficult to secure because of the compound s tendency to decompose. Some values are (Hieber and Schulten, 30) ... 

Although the toxicity of nickel carbonyl is five times as great as carbon monoxide, the available literature data (Armit, 31) indicate that dicobalt octacarbonyl is not as toxic, probably because of its very low vapor pressure. Apparently no investigation has been made into the physiological action of cobalt hydrocarbonyl. It is stated to have an almost intolerable vile odor and its very high vapor pressure is certainly good reason to be extremely cautious in its use. 

A second important focus of our work is the development of suitable analytical methods for the solid state and in solution. The physical characterization of metallo-supramolecular systems has mainly relied on crystal structure determination. Studies have also been performed on surface layers 40-42). The classical analytical methods (like FAB mass spectrometry) or most polymer methods (like light scattering, vapor pressure osmometry or membrane osmometry) can not be used. In solution, ESI mass spectrometry (43-45) and NMR (27,46) have been succesfully applied. We have explored whether MALDI-TOF mass spectrometry in the solid state (Schubert, U. S. Lehn, J.-M. Weidl, C. H. Spickermann, J. Goix, L. Rader, J. Mullen, K., unpublished data.) and sedimentation equilibrium analysis in the analytical ultracentrifuge for solutions may be employed. Grid-like cobalt coordination arrays ([2 X 2] Co(n)-Grid) were used as model systems in the analytical ultracentrifuge (47). 

Cobalt amide is placed in a vapor-pressure eudiometer (see Part 1, Fig. 85) and carefullydecomposed at 50-70°C in the absence... 

Zhu] Zhukov, E.G., Indosova, V.M., Kalinnikov, V.T., Vapor Pressure over die Iron and Cobalt Thiochromites (in Russian), Izv. Akad. Nauk SSSR. Neorg. Mater., 18(4), 688—689 (1982) (Experimental, Thermodyn., 4)... 

IRON/III/. AND COBALT/III/ AND THE VAPOR PRESSURE OF TRIS/ACETYLACETONATO/IRON/III/. IV. 

Chlorotrifluoroethylene polymer vapor degreasing 2,3-Dihydrodecafluoropentane Trichlorotrifluoroethane vapor permeability enhancer, copolymer film Diacetone acrylamide vapor plating, cobalt Cobalt acetylacetonate vapor pressure depressant, aerosols 1,1,1-Trichloroethane vapor-phase deposition, tungsten Tungsten hexafluoride varistor mfg., electronics Cobalt (II, III) oxide varnish Isobutyric acid varnish ingredient 2,2, 4,4, 5,5 -Hexachlorobiphenyl varnish ingredient, rosin Rosin... 

The only thermodynamic study of the system was performed by [1989Hay] who used torsion effusion method for measuring Mn vapor pressure in alloys with iron to cobalt ratio 1.05 and Mn content 10.8 to 93.7 at.% at 977 to 1177°C. The alloys of the Fe-Mn and Co-Mn edges with the same Mn content range were also studied. 

Reduction and Promoters. Cobalt catalysts need to be reduced to the metal before being loaded into the FT reactors. Reduction is carried out with hydrogen from 250 to 450° C. High linear gas velocities are used to minimize the vapor pressure of the water produced, which would otherwise enhance sintering of the Co particles. TPR studies show that reduction of C03O4 starts at about... 

The specifications (June, 1961) of the NGAA (Natural Gasoline Association of America) for commercial propane and commercial butane require (1) a minimum of 95 per cent of propane and/or propylene (or butanes and/or butylenes), (2) no hydrogen sulfide, (3) a negative copper-strip corroaon test (3 hr at 122 F), (4) no water by the cobalt bromide test, and (5) a maximum of 15 grains per 100 cu ft of total sulfur. The vapor pressure of propane must be below 215 psi at 100 F and of butane below 70 psi. 

Because they have low vapor pressures, transition metals cannot be loaded by direct adsorption, but their adsorption can be mediated by transient organo-metallic complexes formed between zerovalent metal atoms and solvent molecules. This is the basis of the solvated metal atom dispersion (SMAD) method developed by Klabunde and Tanaka [72]. Metal vapors condensed in Hquid hydrocarbons at low temperatures form weak complexes that are easily decomposed even below room temperature. Microporous supports impregnated with solutions of metal complexes at low temperatures are warmed up to decompose the complex and liberate zerovalent metal atoms which nucleate into clusters. Preparation of Ni- and Co-clusters in HY and HZSM-5 was reported [72]. In the same way, Nazar et al. [64] condensed iron and cobalt vapors in a slurry of dehydrated NaY zeolite in toluene at -120 °C, then the mixture was rotated at-78°C. The bis-toluene complex thus formed and adsorbed in the zeoUte was decomposed by warming to room temperature yielding clusters small enough to fit into supercages. 

The predominant process for manufacture of aniline is the catalytic reduction of nitroben2ene [98-95-3] ixh. hydrogen. The reduction is carried out in the vapor phase (50—55) or Hquid phase (56—60). A fixed-bed reactor is commonly used for the vapor-phase process and the reactor is operated under pressure. A number of catalysts have been cited and include copper, copper on siHca, copper oxide, sulfides of nickel, molybdenum, tungsten, and palladium—vanadium on alumina or Htbium—aluminum spinels. Catalysts cited for the Hquid-phase processes include nickel, copper or cobalt supported on a suitable inert carrier, and palladium or platinum or their mixtures supported on carbon. 

The oxidation of cyclohexane to a mixture of cyclohexanol and cyclohexanone, known as KA-od (ketone—alcohol, cyclohexanone—cyclohexanol cmde mixture), is used for most production (1). The earlier technology that used an oxidation catalyst such as cobalt naphthenate at 180—250°C at low conversions (2) has been improved. Cyclohexanol can be obtained through a boric acid-catalyzed cyclohexane oxidation at 140—180°C with up to 10% conversion (3). Unreacted cyclohexane is recycled and the product mixture is separated by vacuum distillation. The hydrogenation of phenol to a mixture of cyclohexanol and cyclohexanone is usually carried out at elevated temperatures and pressure ia either the Hquid (4) or ia the vapor phase (5) catalyzed by nickel. 

Cyclohexanol and cyclohexanone are made by the air oxidation of cyclohexane (81%) with a cobalt(II) naphthenate or acetate or benzoyl peroxide catalyst at 125-160°C and 50-250 psi. Also used in the manufacture of this mixture is the hydrogenation of phenol at elevated temperatures and pressures, in either the liquid or vapor phase (19%). The ratio of alcohol to ketone varies with the conditions and catalysts. 

Carbonylation of methanol to form acetic acid has been performed industrially using carbonyl complexes of cobalt ( ) or rhodium (2 ) and iodide promoter in the liquid phase. Recently, it has been claimed that nickel carbonyl or other nickel compounds are effective catalysts for the reaction at pressure as low as 30 atm (2/4), For the rhodium catalyst, the conditions are fairly mild (175 C and 28 atm) and the product selectivity is excellent (99% based on methanol). However, the process has the disadvantages that the proven reserves of rhodium are quite limited in both location and quantity and that the reaction medium is highly corrosive. It is highly desirable, therefore, to develop a vapor phase process, which is free from the corrosion problem, utilizing a base metal catalyst. The authors have already reported that nickel on activated carbon exhibits excellent catalytic activity for the carbonylation of... 

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