Volume 1

Watts' dictionary of chemistry / revised and entirely rewritten by H. Forster Morley and M.M. Pattison Muir ; assisted by eminent contributors.

  • Henry Watts
Date:
1888-1894
Catalogue details

Licence: Public Domain Mark

Credit: Watts' dictionary of chemistry / revised and entirely rewritten by H. Forster Morley and M.M. Pattison Muir ; assisted by eminent contributors. Source: Wellcome Collection.

    751/800 page 725
    Cerous bromide. Ce.,Br6 or CeBr3. Known as the hydrate CeBr3.a:H20. Obtained by dis- solving cerous oxide, Ce,03, in HBrAq and evaporating. Deliquescent needles ; unchanged by heating out of contact with air; heated in air, partially decomposed with loss of Br. Forms double salt CeBr3.AuBr3.8H..O (Jolin, Bl. [2] 21, 323). Cerous chloride. Ce2Cl6 or CeCl3. Ob- tained by heating Ce in Cl; or by dissolving Ce203 in HClAq, adding NH4C1, evaporating to dryness, and driving off Nil.,Cl by heating; or by passing a mixture of dry CO and Cl over hot Ce203 (Didier, C. R. 101, 882). Pure CeCl3 was prepared by Robinson (Pr. 37, 150) by heating pure Ce,(C204)3 in pure dry HC1 gas to 120°-130° for some time, then to 200°, and then to low redness ; the small quantity of C separated was removed by heating at low redness in mixed C02 and HC1; finally the temperature was raised to a full red heat and the C02 stream was stopped. The chloride was allowed to cool in HC1 gas, transferred to a small flask, and kept in vacuo, over H2S04 and surrounded by CaO, until all HC1 was removed. S.G. 3-88 (Robinson, Z.c.). A white, deliquescent solid; easily soluble in water with production of heat; decomposed by 0, or by steam, to Ce203 (Didier). A hydrate, CeCl3.7H20, is said to be formed by digesting Ce203 in HClAq and evaporating. Various double salts are described; e.g. CeCl3.4HgCl,.10H.,O, CeCl3.PtCl4.13H,0, CeCl3.AuCl3.13H20 (Jolin, l.c.). Cerous cyanide (and double cyanides) v. Cyanides. Cerous fluoride. CeF:J. Obtained as a gelatinous pp. (2CeF3H.,0) by adding NaFAq to CeCl3 in HClAq (Jolin).' Ceric fluoride. CeF4.IL,0. An amorphous brown powder, insoluble in water, obtained by treating Ce0.2.6H20 with HFAq, washing, and drying at 100°. Decomposed by heat with loss of H,0 and HF and formation of CeF3; heated strongly in contact with moist air Ce02 and HF are formed. Combines with KF (by treatment with KF.HF) to form 2CeF4.3KF.2H.,0 (Brauner, C. J. 41, 69). Cerous iodide. Ce2I„ or Cel3. Obtained as the hydrate CeI3.9H20, in colourless crystals, by dissolving Ce203 in HIAq, evaporating in a current of H2S, and placing in vacua over H2SO,: soluble in water and alcohol, very quickly decomposes in air (Lange, J. pr. 82, 134). Cerium oxychlorides. The compound Ce,03Cl„ (= Ce203.2CeCl3) is said to be formed when CeCL, is heated with Na (in preparation of Ce) and the mass is treated with water. Dark purple, lustrous, powder; insoluble in water (Wohler, A. 144, 254). The same oxychloride is said to be obtained, as iridescent scales, by passing a mixture of steam and N over a fused mixture of CeCl3 and NaCl; easily soluble in dilute acids; heated in air gives Ce203 and HC1 (Didier, G. R. 101, 882). Cerium, hydroxides of, v. Cerium, oxides of. Cerium, oxides and hydrated oxides of. The best studied oxides are cerous oxide Co203, and ceric oxide Ce02; a peroxide Ce03 also pro- bably exists. Other oxides, e.g. Ce20a and Ce,0„, have been described, but their existence is very doubtful. Cerous oxide. Ce203. (Cerium sesguioxide.) Mol. w. unknown. The white, bulky pp. ob- tained by adding KOHAq to a solution of a cerous salt is hydrated cerous oxide ; as the pp. at once begins to take up O and C02 from the air the hydrate has not yet been obtained pure. The oxide Ce203 is prepared by heating cerous oxalate in a stream of pure H. The oxalate is prepared from the basic nitrate (v. Cerium, Pre- paration) by dissolving in a little HN03Aq and ppg. by oxalic acid (Popp, A. 131, 361; Ram- melsberg, B. 6, 86). Properties and Reactions.—A grey solid; unchanged by heating in H. Dissolves in many acids to form cerous salts of the form Ce.,X3, X= S04, C03, 2N03, 2C104, &c. Cerio oxide. Ce02. (Cerium dioxide). The pale yellow pp. obtained by suspending Ce203.xH20 in KOHAq and passing in Cl is hy- drated ceric oxide (2Ce02.3H„0 ; Rammelsberg, P. 108, 40). Formation.—1. By washing the hydrate with water containing a little acetic acid until KOH is removed, drying and heating.—2. By heating cerous sulphate Ce23S04 to full redness in air. 3. By heating CeF4 in air (Brauner). Preparation.—Cerous oxalate is prepared from the basic nitrate from cerite (v. Cerium, Preparation); it is heated to redness in a Pt dish with free access of air. Nordenskiold (P. 114, 616) obtained colourless, transparent, tesseral crystals of Ce02 by heating CeO, for 24 hours with a little borax in a porcelain oven, and treating the mass with HClAq: S.G. at 15° = 6-94. Properties and Reactions.—Very pale yellow solid (Wolf, Brauner, Robinson [C. N. 54], Crookes, Pr. 38, 414). S.G. 6-74 (Nilson a. Pet- tersson, B. 13, 1459). S.V.S. 25-45. S.H. •0877 (N. a. P., Pr. 31, 46). Dissolves in cone. H2S04Aq with production of much heat, and evolution of some O ; on crystallising, the salt Ce,3S04.Ce(S04)„.24H,0 separates (Mendelejeff, A. 168, 45); from the mother-liquor of this salt ceric sulphate Ce2S04.4H20 is obtained. This reaction shows that part of the CeO„ is re- duced by the H2S04 to Ce ,0.„ and part reacts with the acid to form Ce2S04. Dissolves in HN03Aq; on adding NH4N03 and crystallising in vacuo the double salt 2Ce(N03)4. 4NH,N03.3H20 is obtained. Dissolves in warm HClAq with evolution of Cl and formation of Ce,Cl0. Dis- solves easily in dilute acids in presence of re- ducing agents, e.g. alcohol, SO,Aq, &c. Cerium trioxide. Ce03. (Cerium peroxide.) Said to be obtained as a reddish pp. by adding a slight excess of NH3Aq to Ce23SO ,Aq, and di- gesting with hydrogen peroxide (de Boisbaudran, C. R. 100, 605 ; Cleve, Bl. [2] 43, 53). Other oxides of cerium are described by Popp (A. 131, 361); Hermann (J. pr. 30, 184 ; 82, 385 ; 92, 113); the formulas Ce,09 and Ce,Or> are assigned to these oxides, respectively; but experiments made by Rammelsberg (P. 108, 40) and others tend to show that the only oxides which have been isolated are Ce203, Ce02, and CeO.,. Cerium, oxychlorides of, v. under Cerium, haloid and oxyiialoid compounds of.
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