Volume 1

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

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.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    718/796 (page 692)
    a weak acid (v. Cabbonic acid). Absorbed by moist alkalis and alkaline earths forming carbo- nates ; rapidly absorbed by mixture of powdered KOH and hydrated Na2S04. Poisonous, by cutting off supply of 0. liquid carbon dioxide is a limpid, colourless, refractive, liquid ; nonconductor of electricity ; not changed by strong induction-sparks ; very expansible by heat; C.E. is greater than that of the gas. Insol. in water which swims on the surface; mixes with alcohol, ether, <fec. Does not dissolve S or P; dissolves I; no reaction with Na or K (Cailletet, C. B. 75, 1271). Solid carbon dioxide is a white, loose, snow- like, solid; when compressed by hammering in wooden moulds it resembles chalk (Landolt, B. 17, 309). Very bad conductor of heat. Evapo- rates slowly, a specimen prepared by Landolt 53 mm. by 71 mm. diam. took 5 hours to volatilise in the air. Burns, if pressed against the skin. Beactions.—l. Heated to c. 1300° in porcelain tube is partly changed to CO and O (Deville, C. B. 56, 729; v. also Berthelot, C. B. 68, 1035).—2. Partly decomposed by electric sparks; a condition of equilibrium is attained when change of CO., into CO + O equals that of CO and O into C02 (Dixon a. Lowe, C. J. 47, 571).— 3. Mixed with hydrogen, and heated to bright redness or submitted to induction-sparks, H20 and CO are formed; if H.,0 is removed the whole of the C02 goes to CO (Dixon, C. J. 49, 94). According to Dubrunfaut (C. B. 74, 125) CO, and H passed over hot pumice give C and H20.—4. A mixture of carbon dioxide and sul- phur vapour passed through a red-hot tube yield a little COS, CO, and S02 (Berthelot, Bl. [2] 40, 362).—5. With sulphuretted hydrogen, passed through red-hot tube, forms CO, H,0 and S (Kohler, B.W, 205).—6. Decomposed by chloro- phyll--pa,rts of plants in sunshine.—7. Keduced to CO by heating with carbon, iron or zinc, or with copper which has occluded hydrogen (Tis- sandier, C. B. 74, 531; Schrotter, W. A. B. 34, 27).—8. Partly reduced to CO by reaction with ferrous sulpJiate and a little water, in a closed tube (Horsford, B. 6, 1390).—9. Eeduced to C by heating strongly with sodium, potassium, or magnesium; alkali carbonates strongly heated with phosphorus or boron giveC02which is reduced to C (Tennant, Crellis A. [1793] 1,158 ; Dragen- dorff, J. 1861. Ill; Leeds, B. 12,1834 a. 2131).— 10. With moist alkalis, or alkaline earths, forms carbonates.—11. With water probably forms a solution of carbonic acid, H2C03 (v. Cakbonic acid).—12. With sodium- or potassium-amalgam at c. 350° gives Na (or K) oxalate (Drechsel, A. 146, 141).—13. With sodium C02Aq reacts to give Na formate (Kolbe a. Schmitt, A. 119, 251). 14. Decomposes moist potassium iodide at high temperature giving HI (Papasogli, G. 1881. 227). Carbon, oxybromide of. The existence of a Br compound of CO analogous to COCl2 is doubtful. A mixture of Br vapour with excess of CO is slowly, but not fully, decolourised in sunlight; in contact with KOHAq this gas pro- duces KBr and K2C03 (Schiel, A. Suppl. 2, 311). Emmerling a. Lengyel could not obtain a trace of any compound of C, Br, and O, by the re- action between COS and Br at a high tempera- ture (B. 2, 547). By the reaction between H,S04 (50 parts), K2Cr207 (20-25 parts), and CHBr3 (5-10 parts), Emmerling (B. 13, 874) obtained a small quantity of a liquid, which he slowly distilled through Sb, to remove Br; he thus obtained a colourless heavy liquid, smell- ing like COCl2. The B.P. rose from 12° to 30° ; analyses seemed to show that the liquid was a mixture of COCl2 and C oxybromide. Carbon, oxychloride of. C0C12. (Carbonyl chloride. Bhosgene gas. Chloro-carbonic acid.) Mol.w. 98-67. (8-2° at 756 mm.). S.G. -f (liquid) 1-432; 1-392 (Emmerling a. Lengyel, A. Suppl. 7,101). V.D. 50-6 (E. a. L.). [C,0,CF] = 54,850 at constant volume; 55,140 at constant pressure (Thomsen). First prepared by J. Davy in 1811 (T. 1812. 144) by the action of sunlight on C1 + CO (hence the name phosgene). Formation.—1. By leading CO into boiling SbCl5 (Hofmann, A. 70, 139 ; v. also Butlerow, Z. 1863. 484 ; Kraut, Gm.-K. I. 2, 386), or over hot PbCl2 or AgCl (Gobel, J.pr. 6, 388).—2. By heating CC14 with ZnO at 200° in a closed tube ; or by passing CC14 and CO through pumice in a tube heated to about 400°.—3. By heating CHC13 (1 part), K2Cr207 (2£ parts), and H2S04 (10 parts) at 100°, and passing the gas over Sb to absorb CI (E. a. L.).—4. By passing CI and CO overPt black at about 400° (Schiitzenberger, Bl. [2] 10, 188; 12, 198).—5. By passing CI and C02 over hot C (Schiel, J.pr. 6, 388). (For other methods v. Schiitzenberger, B. 2, 218; Dewar a. Cranston, C. N. 22, 174; Armstrong, B. 3, 730.) Breparation.—Dry CI and dry CO are slowly passed through a succession of large bottles freely exposed to sunlight, then through a U - tube loosely filled with pieces of Sb (to remove free CI), and finally into a tube surrounded by snow and salt. Each gas should pass through the drying-bottles at as nearly as may be the same rate. 100 litres CO give 140-150 g. COCl2 in direct sunlight. Paterno (G. 5, 233) passes the mixed gases through a tube 400 mm. long filled with animal charcoal: combination occurs with production of heat; the tube must be cooled by a wet cloth from time to time (v. also Wilm a. Wischin, A. 147,150). Broperties.—Colourless gas with penetrating odour ; at 8° and under it is a colourless limpid liquid; the gas is soluble in acetic acid, benzene, and several liquid hydrocarbons. Beactions.—1. Water absorbs COCl2 with formation of CO.Aq and HClAq. Berthelot (C.B. 87,591) gives the value [COCl-,Aq] = 64,600. 2. Alcohol forms chlorocarbonic ether CO.Cl.OEt (q. v.). — 3. Several metals decompose COCl2, when heated with it, to CO and metallic chloride; e.g. Sb, As, Na, Sn, Zn ; potassium forms KG, K2C03, and C.—4. With slightly moist potassium carbonate, KC1, H20, and C02 are formed.— 5. Zinc oxide produces ZnCl2 and C02.—6. Com- bines with 4 vols, ammonia to form urea and NH4C1 (Natanson, A. 98, 288; Fenton, C. J. 35, 793). Carbon, oxysulphide of. COS. (Carbonyl sulphide.) Mol. w. 59-91. V.D. 30-4. [CO,S] = 8,030 ; [C,0,S] = 37,030; [COS.O3] = 131,010 (Thomsen). Occurrence.—According to Thorn (A. Suppl.