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Encyclopedia Britannica - Main :: NAN-NEW |
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NEW CALEDONIA 1900. 1901. 1902. 1903. 1904. 1905. 1906. 1907. 1908. Metric tons . 100,319 133,676 129,653 77,360 98,665 125,289 130,688 101,708 120,028 (See Rothwell's Mineral
The metal may also be obtained on the small scale by the reduction of the oxide
Berzelius
It is a greyish white metal, and is very malleable and ductile. Its specific gravity varies according to the method employed for its preparation, the extreme values being 8.279 and 9.25. It melts between 1400-1600 C. Its specific heat increases with rise of temperature, the mean value from 15 to loo C. being o 1084 (A. Naccari, Gaze., 1888, 18, p. 13). It is magnetic, but loses its magnetism when heated, the loss being complete at about 340-3500 C. On the physical constants see H. Copaux, Comptes rend us, 1905, 140, p. 651. Nickel occludes hydrogen readily, is attacked by the halogen elements, and oxidizes easily when heated in air. In the massive state it is unacted upon by dry air, but if moistened with acidified water, oxidation takes place slowly. When obtained by reduction processes at as low a temperature as possible the finely divided metal so formed is pyrophoric, and according to P. Schutzenberger (Comptes rendus, 1891, 113, p. 177) dry hydrochloric acid gas converts this form into nickel chloride and a volatile compound of composition NiHC1. It decomposes water at a red heat. According to E. St Edme (Comptes rend us, 1886, ro6, p. 1079) sheet nickel is passive to nitric acid, and the metal remains passive even when heated to redness in a current of hydrogen. On the reduction of organic compounds by hydrogen in the presence of metallic nickel see P. Sabatier and J. B. Senderens, Ann. Chico. Phys., 1905 [8], 4, pp. 319, 433. It rapidly oxidizes when fused with caustic soda, but is scarcely acted upon by caustic potash (W. Dittmar, Jour. Soc. Chem. Ind., 1884, 3, p. 103). Hydrochloric and sulphuric acids are almost without action on the metal, but it dissolves readily in dilute nitric acid. Nickel salts are antiseptic; they arrest fermentation and stop the growth of plants. Nickel carbonyl, however, is extremely poisonous. On the toxic properties of ( Liebig
Nickel fluoride, NiF2, obtained by the action of hydrofluoric acid on nickel chloride, crystallizes in yellowish green prisms which volatilise above loon C. It is difficultly soluble in water, and combines with the alkaline fluorides to form double salts. Nickel chloride, NiC12, is obtained in the anhydrous condition by heating the hydrated salt to 14o C., or by gently heating the finely divided metal in a current of chlorine. It readily sublimes when heated in a current of chlorine, forming golden yellow scales. It is easily reduced when heated in hydrogen. It forms crystalline compounds with ammonia and the organic bases. It is soluble in alcohol and in water. Three hydrated forms are known, viz. a mono-, di-, and hexa-hydrate; the latter being the form usually obtained by the solution of the oxide
Several sulphides of the element
hydroxylamine
Nickel carbonyl, Ni(CO)4, is obtained as a colourless mobile liquid by passing carbon monoxide over reduced nickel at a temperature of about 6o C. (L. Mond
critical pressure is 30 atmospheres and its critical temperature is in the neighbourhood of 195 C. (J. Dewar, Proc. Roy. Soc., 1903, 71, p. 427). It decomposes with explosive violence when heated rapidly. Dewar and Jones (Journ. Chem. Soc., 1904, p. 203) have made an exhaustive study of its reactions, and find that it is decomposed by the halogens (dissolved in carbon tetrachloride) with liberation of carbon monoxide and formation of a nickel halide. Cyanogen iodide and iodine mono- and tri-chloride effect similar decompositions with simultaneous liberation of iodine; sulphuric acid reacts slowly, forming nickel sulphate and liberating hydrogen and carbon monoxide. Hydrochloric and hydrobromic acids are without action; hvdriodic acid only reacts slowly. With aromatic hydrocarbons in the presence of anhydrous aluminium chloride, in the cold, there is a large evolution of hydrochloric acid gas, and an aldehyde is formed ; at loo C., on the other hand, anthracene derivatives are produced. Thus by using benzene, benzaldehyde and anthracene are obtained. Dewar and Jones suggest that in the latter reaction it is themetallic nickel which is probably the reducing agent effecting the change , since it is only dissolved in any quantity when the anthracene hydrocarbon is produced. When mesitylene is used, the reaction does not proceed beyond the aldehyde stage since hydrocarbon formation is prevented by the presence of a methyl group in the ortho-position to the -CHO group. Acids and alkalis are in general without action on nickel carbonyl. The vapour of nickel carbonyl burns with a luminous flame, a cold surface depressed in the flame being covered with a black deposit of nickel. It is an extremely powerful poison. Mond
Numerous determinations of the atomic weight of nickel have been published, the values obtained varying from 58.o to approximately 59.5 The more recent
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