Notes on analytical chemistry for students in medicine : extracted from the fifth edition of "Notes for students in chemistry" / by Albert J. Bernays.

  • Albert Bernays
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Notes on analytical chemistry for students in medicine : extracted from the fifth edition of "Notes for students in chemistry" / by Albert J. Bernays. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

    42/182 (page 30)
    COBALT AND NICKEL IN GROUP IV. 22. Cobalt, Co = 58-6. White, reddish-tinted metal. Slightly magnetic, malleable, tenacious. Dyad. Sp. gr. 8'7. Melts at lower temperature than Iron. Readily dis- solved by Nitric acid to Cobalt nitrate, Co2N03; slowly dissolved by dilute HC1 and dilute Sulphuric acid. .Cobalt oxide, CoO, is greenish-brown, insoluble in water. Cobalt Hydroxide, CoH,02, is rose-red; soluble in NH4OH, with reddish color. Chief salts: CoS04,7H?0; Co2N03,6H20; CoCl2.6H20. Acid reaction. Solutions blue, red or pink. HC1 may change the red color to blue. NH4C1 -f- NH4OH no precipitate, but becoming reddish-brown on exposure. Sodic carbonate, a lilac precipitate of 3CoO,2CoC03,-iH20. Tests for Cobalt in soluble salts. IV. NH4C1+(NH4)2S, black ppt. of CoS,H20, insoluble in dilute HC1: soluble in Aqua regia. KOH blue basic Cobaltic salt precipitated, turning green on exposure; into pale-red hydroxide CoH202, on boiling. NH4OH, blue basic salt, readily soluble in excess, ■with greenish color, browning on exposure; ultimately red. (NH4)2C03, peach-colored basic carbonate, readily soluble in excess with magenta color. K4FeCy6, greenish precipitate. K3FeCy6, brownish-red precipitate. [On addition of tartaric acid to a fresh sample, then of ammonia, and then of ferricyanide of potassium, a deep yellowish-red color ensues. Thus may Cobalt be detected in presence of Nickel.] KN02, together with Acetic acid, yields after a time a bright yellow precipitate of cobalt-potassium nitrite.] [KCy, brownish-white CoCy2, easily soluble in excess as 2KCy, CoCy2, and precipitated by HC1; not precipitated after boiling, as Cobalticyanide of potassium, K3CoCy6 is formed.] [Ca2C10 gives a black precipitate of Cobaltic hydrate Co.,03. 3H20.] On Charcoal similar to Iron, but more metallic. Borax bead colored blue in outer and inner flame. 23. Nickel, Ni = 58-6. White metal. Dyad. Sp. gr. 8-8. Melts more readily than Iron. Dilute Nitric acid a ready solvent, to Nickel nitrate. Concentrated HN03 renders it passive. Dilute Hydrochloric and Sulphuric acids slowly dissolve it. Kupfer-nickel, Ni2S2, is its chief Ore. Arsenical nickel, NiAsS2, is also an Ore. The metal obtained from the Oxide by strongly heating with Carbon; or from the oxalate NiC204 by heat. Nickel oxide is grey; Hydroxide, NiH202, unripe apple-green. Soluble salts are green, and redden litmus. Chief salts: NiCl2,9H20 ; NiS04, 7H20 ; Ni2N03,6H20. Sodium carbonate precipitates green basic carbonate. NH4C1 + NH4OH, a plum-colored liquid, so that Nickel is really detected in Group III.