Nickel vapor pressure

Tungsten hexafluoride is shipped as a Hquid under its own vapor pressure in nickel or steel cylinders in quantities of 45 kilograms per cylinder or less however, it has been shown that the purity of WF packaged in steel cylinders can degrade over time (21). It is classified as a corrosive Hquid by the... 

The behavior of materials, particularly steel, in cavitating fluids results in an erosion mechanism, including mechanical erosion and electrochemical corrosion. The straightforward way to fight cavitation is to use hardened materials, chromium, chrome-nickel compounds, or elastomeric plastics. Other cures are to reduce the vapor pressure with additives, reduce the turbulence, change the liquid s temperature, or add air to act as a cushion for the collapsing bubbles. 

Next, let the example of vanadium, which, in the as-reduced condition, may contain a variety of impurities (including aluminum, calcium, chromium, copper, iron, molybdenum, nickel, lead, titanium, and zinc) be considered. Vanadium melts at 1910 °C, and at this temperature it is considerably less volatile than many of the impurity metals present in it. The vapor pressure of pure vanadium at this temperature is 0.02 torr, whereas those of the impurity elements in their pure states are the following aluminum 22 torr calcium 1 atm, chromium 6 torr copper 23 torr iron 2 torr molybdenum 6 1CT6 torr nickel 1 torr lead 1 torr titanium 0.1 torr and zinc 1 atm. However, since most of these impurities form a dilute solution in vanadium, their actual partial pressures over vanadium are considerably lower than the values indicated. Taking this into account, the vaporization rate, mA, of an element A (the evaporating species) can be approximated by the following free evaporation equation (Langmuir equation) ... 

In this equation, a and b are constants characteristic of the system. The modified mole fraction is the one defined by Lu (34) from the compositions on a salt-free basis and from the vapor pressure of the pure components and of the salt plus pure liquid solutions. Figures 5 and 6 show the values of X i and X+i corresponding, respectively, to ethanol and water for each of the three systems. For nickel(II) chloride and strontium chloride, the experimental data follow a straight line, while for copper(II) chloride the data form three straight lines, as was expected (24) from the maximum and minimum in the temperature diagram. 

About 1.5 g of nickel was vaporized at 1823 K over 30 min from a resistively heated alumina-coated molybdenum wire spiral inside an evacuated 200-mm diameter glass vessel which was partly immersed in liquid nitrogen. About 20 g of the allyl halide was simultaneously vaporized into the vessel and condensed with the nickel vapor on the cold walls. During this cocondensation, the pressure in the vessel was below 2 x 10 4Torr so that few gas-phase intermolecular collisions occurred. 

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 series of V,V -bridged bis(2,4-pentanedione-iminoato) nickel(II) complexes (5a-5d) was studied by TG and DTA to determine equilibrium vapor pressures and enthalpies of sublimation and vaporization. Complexes 5a and 5c were found to be best suited to serve... 

The null point (no pressure difference across the nickel diaphragm) was established by closing valves A and C and opening valves B and D. For vapor pressure readings, the sample system and gauge were... 

Quite recently, Kruck 118) obtained 80% yields of tetrakistrifiuoro-phosphine nickel by reaction at 100° C. and 350 atm. Clark and co-worker 56) studied the reaction mixture of Ni(CO)4 and PF3 by gas chromatography and NMR, determining the physical constants (density, vapor pressure) of all the substitution products, and showing that in first approximation the equilibrium composition of the mixture can be calculated if there was a statistical equilibrium between the ligands CO and PF3. This means that the metal-to-ligand bonds are of the same strength. 

The enthalpy of formation for Ni(g) is obtained by an analysis of the vapor pressure data of Morris et al. ( ). In this study a gas-transport method was used to measure vapor pressures (16 points) over liquid nickel in the range 1816-1895 K. For... 

Rosenqvist ( ) studied the sulfur vapor pressure above solid nickel sulfides using the equilibrium. Combining his... 

A simple, rapid, and reliable viscometric technique for evaluating the protective capacity of commercially available materials as inhibitors of ozone-induced polymer chain scission has been described (1). This work included the results of an evaluation of several chemicals such as A,A -di-sec-butyl-p-phenylenediamine, nickel dibutyl di-thiocarbamate, l-(m-aminophenyl)-2,5-dimethylpyrrole, and 2,6-di-tert-butyl-4-methyl-phenol as antiozonants A,A -di-sec-butyl-p-phenylenediamine exhibited superior inhibiting characteristics. However, because of the potential toxic effects and relatively high vapor pressure of this chemical, its use is considered impractical. 

Liquid, mp 19.5° bp 47.9°. dfs 2.502. Heat of vaporization ]0.60 kcal/mole. Appreciable vapor pressure at room temp. Hydrolyzed by water, di] alkali. Soly in anhydrous HF 3.3 moles/]. Freely so] in alcnhol, chloroform, acetone, ligroin. Insol in carbon disulfide. Dec toluene and ether. Etches glass slowly at room temp more rapidly in presence of mnisture with formation of yellow color. May be stored in sealed vessels made from iron, nickel, copper, platinum. 

PEA/ECK] Pearce, J. N., Eckstrom, H. C., The vapor pressures and some thermodynamic properties of aqueous solutions of nickel chloride at 25 C, J. Phys. Chem., 41, (1937), 563-567. Cited on pages 128, 423. 

MOR/ZEL] Morris, J. P., Zellars, G. R., Payne, S. L., Kipp, R. L., Vapor pressures of liquid iron and liquid nickel. Bureau of Mines, Report of investigations 5364, (1957). Cited on pages 75, 287. 

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