Nickel liquid

The enthalpy of formation of Ni(l) can be calculated from that of Ni(cr) by adding the enthalpy of fusion and the difference in enthalpy, (// , (1728 K) - //° (298.15 K)) between the solid and liquid phase. The value 

The enthalpy of fusion retained by this review is identical with that given in the NIST-JANAF Tables [98CHA]. The compilations [73HUL/DES] and [77BAR/KNA] adopted the value determined by [63GEO/FER]. 

The entropy at 298.15 K can be calculated in a maimer analogous to the one used for the enthalpy of formation of nickel in the liquid region. The value selected by this review  

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Fig. 18.3 Iron meteorites have a chtiracteristic texture which appears on polished and etched surfaces. This texture, called the Widmanstatten pattern, formed during slow cooling and crystallization of liquid iron-nickel in the core of a meteorite parent body. The tear-shaped inclusion is composed of iron sulfide which is immiscible in iron-nickel liquid. The meteorite in this image is Carbo, a IID iron meteorite, which was not collected in Antarctica (Reproduced by permission of H. Haack from Htiack and McCoy (2005, Fig. 8, p. 337) and Elsevier, Inc. through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01932)...

When the vapor-gas mixture is fed to the liquid shell surface, there arises a catalytic reaction of decomposition of a carbon-containing organic compound with dissolution of carbon in the nickel liquid phase. A saturation of the nickel liquid layer with carbon increases its thickness and decreases the surface curvature. This disturbs the system from equilibrium (Fig. 25 (b)) as the liquid-layer thickness increases, the lines of equilibrium between the liquid layer and the crystalline core shift towards higher temperatures (see relationship (10)). 

This results in the initiation of the crystallization, which increases the volume of the crystalline core of the nickel droplet at the expense of nickel from the liquid shell and as a consequence, decreases the volume of the liquid shell (Fig. 25 (c)). In this case, since the solubility of carbon in the nickel liquid phase is much higher than that in the solid phase, carbon remains in the liquid phase and its concentration in the phase sharply increases. Eventually, this results in a supersaturation of the liquid with carbon and the transition to the two-phase region L+C of the coexistence of crystalline carbon and liquid i.e., carbon precipitates as an individual crystalline phase in the form of nanotubes (Fig. 25(d)). 

CH3CH1CH2CH2OCH2CH2OH. Colourless liquid with a pleasant odour b.p. 17rC. Manufactured by heating ethylene oxide with 1-butanol in the presence of nickel sulphate as a catalyst. Used as a solvent in brushing lacquers. 

It also forms compounds known as carbonyls with many metals. The best known is nickel tetracarbonyl, Ni(CO)4, a volatile liquid, clearly covalent. Here, donation of two electrons by each carbon atom brings the nickel valency shell up to that of krypton (28 -E 4 x 2) the structure may be written Ni( <- 0=0)4. (The actual structure is more accurately represented as a resonance hybrid of Ni( <- 0=0)4 and Ni(=C=0)4 with the valency shell of nickel further expanded.) Nickel tetracarbonyl has a tetrahedral configuration,... 

Nickel tetracarbonyl Ni(CO)4 was the first metal carbonyl to be discovered, by Mond in 1890 it is obtained by passage of carbon monoxide over nickel metal heated to 320 K. It is a volatile, toxic liquid (b.p. 315 K), and has a tetrahedral structure. It has considerable stability, but inflames in air it is believed that in the structure... 

P-Phenylethylamine is conveniently prepared by the hydrogenation under pressure of benzyl cyanide with Raney nickel catalyst (see Section VI,5) in the presence of either a saturated solution of dry ammonia in anhydrous methyl alcohol or of liquid ammonia the latter are added to suppress the formation of the secondary amine, di- P phenylethylamine ... 

Single-bond cleavage with molecular hydrogen is termed hydrogenolysis. Palladium is the best catalyst for this purpose, platinum is not useful. Desulfurizations are most efficiently per-formed with Raney nickel (with or without hydrogen G.R. Pettit, 1962 A or with alkali metals in liquid ammonia or amines. The scheme below summarizes some classes of compounds most susceptible to hydrogenolysis. 

Hydrazine Alkali metals, ammonia, chlorine, chromates and dichromates, copper salts, fluorine, hydrogen peroxide, metallic oxides, nickel, nitric acid, liquid oxygen, zinc diethyl... 

Liquids. Approximately 170,000 railroad tank cars are used in the United States. The interior surfaces of these cars are tailored to carry a wide variety of products and are constmcted of steel which is either unlined or lined with materials to enhance the chemical compatibiUty with a specific product these lining materials include synthetic mbber, phenoHc or modified epoxy resins, or corrosion-resistant materials such as aluminum, nickel-bearing steel, or stainless steel. 

Fig. 6. Section of the Fe—Cr—Ni diagram at 8% nickel (5) where a, y, and represent phases and L = liquid alloy.

Fischer-Tropsch Synthesis The best-known technology for producing hydrocarbons from synthesis gas is the Fischer-Tropsch synthesis. This technology was first demonstrated in Germany in 1902 by Sabatier and Senderens when they hydrogenated carbon monoxide (CO) to methane, using a nickel catalyst. In 1926 Fischer and Tropsch were awarded a patent for the discovery of a catalytic technique to convert synthesis gas to liquid hydrocarbons similar to petroleum. 

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