Inorganic Chemistry. 603

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INORGANIC CHEMISTRY. 603

Inorganic Chemistry.

Intensifying (" Activirende ") Action of Reducing Agents, Colloidal Noble Metals, Alkaloids, and other Basic Substances on Oxidising Agents. By EDUARDSCHAER (Annalen, 1902, 323, 32--82).-The intensifying action of sulphurous acid, hydrogen peroxide, colloidal gold and platinum, alkaloids and insoluble carbonates on certain oxidising agents has been studied, using the oxidisable substances potassium iodide, guaiacum, indigo-carmine pyrogallol, guaiacol, p-phenylenediamine, and aloin as indicators. A description of the experiments made on cupric salts has already been published (this vol., ii, 140). Hydrogen peroxide, like sulphurous acid (Abstr., 1901, ii, 603), intensifies the oxidising action of ferric salts on indigo, and, in addition, promotes the oxidation of guaiacum, potassium iodide, 13-phenylenediamine, and guaiacol. Colloidal platinum, although not inducing any action on indigo, renders the oxidising agent more active towards the other oxidisable substances. Sulphurous acid does not intensify the action of mercuric chloride, and hydrogen peroxide does so only in the case of aloin, Colloidal platinum induces the oxidation of guaiacum and pyrogdlol by this reagent, and both this metal and colloidal gold promote the development of the guaiacol coloration. Pyrogallol is oxidised both by mercuric chloride and ferric salts in the presence of insoluble carbonates and alkaloids. Silver nitrate oxidises indigo and aloin in the presence of hydrogen peroxide, whilst the guaiacum and guaiacol colorations are developed in the presence of the colloidal noble metals, Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. Hydrogen peroxide intensifies the action of chromic acid on all the oxidisable substances under examination (compare Bach, this vol., ii, 251). Sulphurous acid promotes the oxidation of indigo, guaiacum, and aloin, whilst colloidal gold and platinum render the oxidising agent more active towards pyrogallol, p-phenylenediamine, and potassium iodide. Hydrogen peroxide intensifies 'the action of hypochlorous acid on p-phenylenediamine ; the colloidal metals promote the oxidation of guaiacum and aloin by this acid. Chloric acid and the chlorates are rendered more generally active by sulphurous acid, but are not affected by hydrogen peroxide or the colloidal metals. Sulphurous acid has a less marked effect on bromic acid and the bromates; pyrogallol and p-phenylenediamine are attacked by these reagents in the presence of the colloidal metals, which also induce a slight oxidation of aloin. Iodates oxidise indigo, pyrogallol,. p-phenylenediamine, and guaiacol under the influence of sulphurous acid, hydrogen peroxide promotes the oxidation of pyrogallol and p-phenylenediamine ; this effect is likewise produced by colloidal platinum, which also intensifies the action of the oxidising agent on guaiacol and aloin. Nitric acid and the nitrates readiIy oxidise indigo and guaincum View Article Online

604 ABSTRACTS OF CHEMICAL PAPERS,

under the influence of sulphurous acid ; hydrogen peroxide promotes the decomposition of indigo and potassium iodide, whilst the action on pyrogallol, p-phenylenediamine, guaiacol, and the iodide is intensified by the presence of colloidal platinum. Permanganates act more energetically on potassium iodide and p-phenylenediamine in the presence of hydrogen peroxide ; sulphurous acid induces the oxidation of indigo, whilst guaiacum and p-phenylenediamine are oxidised under the influence of colloidal platinum, aloin being also affected by colloidal gold. Benzoic peroxide is rendered more active towards indigo, guaiacum, and guaiacol by the presence of sulphurous acid ; hydrogen peroxide promotes the oxidation of indigo, especially in warm solutions, it also produces a similar effect in the case of p-phenylenediamine. Colloidal platinum also influences the oxidation of indigo in warm solutions, and causes the development of a faint coloration with aloin. Quinone is rendered more active by hydrogen peroxide and colloidal platinum, the first agent promotes the oxidation of indigo, potassium iodide, and guaiacol, whilst the second intensifies the action on guaiacum, pyrogallol, and aloin. The last of these substances and leucaniline are also oxidised by quinone in the presence of sulphurous acid or colloidal gold. G. T. M. Crystallised Hydrogen Peroxide. By WILHELMSTAEDEL (Zeit. angew. Chevn., 1902, 15, 642--643).-When a concentrated solution of hydrogen peroxide is cooled, it solidifies and the crystals melt at -29 A 90-95 per cent. solution remains liquid at -20°, but solidifies in a freezing mixture of ether and carbon dioxide. The eutectic point lies between - 20" and - 23". The crystals, which are anhydrous, are colourless and prismatic. The best method of obtaining anhydrous hydrogen peroxide is by this freezing out process. When

Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. a trace of platinum sponge or manganese dioxide is thrown on to the anhydrous preparation, an explosive decomposition takes place ; a mixture of powdered carbon or magnesium with a trace of manganese dioxide inflames when dropped on to it. When a 90-95 per cent. solution of hydrogen peroxide is added to a concentrated solution of cadmium chloride, silky crystals separate which contain 23 per cent. of hydrogen peroxide. J. McC. Preparation of Sulphuryl Chloride. ALFREDWOHL & OTTORUFF (D.R.-I?. 129862).-The transformation of chlorosulphonic acid into sulphuric acid and sulphuryl chloride in molecular proportion is readily effected by boiling the compound with mercury or mercuric sulphate. If the apparatus is fitted with a reflux condenser at 70", the sulphuryl chloride distils over in quantitative yield, The process is continuous and other metallic salts, such as those of tin and antimony, may be employed as catalysts; sulphur dichloride and iodine mono- chloride also produce the same effect. G. T. M. The Lead Chamber Process in the Light of Physico-chemical Theories. By E. HAAGN(Zeit. arzgew. Chem., 1902, 15, 583-585). -The author believes that the lead chamber process can best be explained by physic0 -chemical theorier on the assumption that View Article Online

INORGANIC CHEMISTRY. 605

nitrosylsulphuric acid is formed as an intermediary product. Since this substance has a very low vapour tension, it is removed from the reaction mixture and thus the reaction is accelerated. J. McC. Theory of the Lead Chamber Process. By GEORGLUNGE (Zeit. angew. Chem., 1902, 15, 581-583. Compare this vol., ii, 315).-A reply to Th. Meyer (Zeit. angew. Chem., 1901, 14, 1245; 1902, 15, 278) and Riedel (this vol., ii, 450). J. McC. Selenium. 11. By JULIIJSMEYER (Zeit. anorg. Chem., 1902, 31, 391--400).-A full account of the determination of the atomic weight of selenium (see this vol., ii, 392). Selenium can be completely reduced and separated in the elementary condition from an acid solution of a selenite by hydrazine. J. McC. Direct Hydrogenation of Nitrogen Oxides by Contact Action. By PAULSABATIER and JEANB. SENDERENS(Compt. rend., 1902, 135, 278--281).-When a mixture of nitrous oxide and hydrogen is passed over reduced nickel, a reaction takes place at the ordinary temperature with a large development of heat, and in presence of excess of hydrogen the oxide is completely reduced without any formation of ammonia. If the oxide is in excess, the front part of the metal becomes incandescent, higher nitrogen oxides appear in the cooler part of the tube, and a little ammonia is formed, Reduced copper behaves in the same way as nickel, but reduction does not take place below 180'. Mixtures of nitric oxide with excess of hydrogen are not reduced by nickel below 180°, but above this temperature water, ammonia, and nitrogen are formed. With excess of nitric oxide, the metal becomes incandescent. Copper behaves in the same way as nickel. With nitrogen peroxide and hydrogen, the phenomena are similar, but if the proportion of the

Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. peroxide is increased, ammonium nitrite and nitrate are formed as well as ammonia, and when the proportion exceeds a certain limit the metal becomes incandescent and an explosion usually occurs. Mixtures of nitric acid vapour and hydrogen are reduced in a similar manner. C. H. B. Reactions in the Formation of Calcium Carbide. By G. GIN (Zeit. Elektrochem., 1902, 8, 397).-Free oxygen is found in the gases formed in the hottest portions of a calcium carbide furnace, whilst calcium vapour is found in cooler portions of the furnace. The author suggests that these substances may be formed by the reactions 2Ca0 + 4C = 3CaC, + 0, and CaCz + 2Ca0 = 3Ca + 2C0, the tern- pernture in the hottest zones of the furnace being higher than the dissociation temperature of carbon monoxide. T. E. Separation of Beryllium. By GREGOIREN. WYROUBOFF(Bull. Xoc. Chim., 1902, [iii], 2'7, 733-734).-For the purpose of separating beryllium from aluminium and iron, which generally accompany it in minerals, the author takes advantage of the fact that beryllium oxalate is very sparingly soluble, whereas the oxalates of aluminium and of iron are comparatively soluble in waber. A. F. VOL. LXXXII. ii. 41 View Article Online

606 ABSTRACTS OF CHEMICAL PAPERS.

Properties and Constitution of Zinc Peroxides. By ROBERT DE FORCRAND(Compt. rend., 1902, 135, 103--106).-The zinc peroxides Zn305,2H,0, Zn30,,3H,0, Zn,O7,4H,0: and 2Zn0,,5H20 (this vol., ii, 322) are stable in moist or dry air with the exception of the last, which at the ordinary temperature gradually changes into Zn30,,2H,0. At 1004 the compound Zn40,,4H,O is gradually converted into Zn,0,,3H20, but both the hydrates of the oxide Zn305are stable at this temperature. The compound Zn30,,3H,0 at 190' and the compound Zn30,,2H,0 at 210' suddenly lose water and oxygen and are converted into the monoxide, All of them dissolve in dilute sulphuric acid without liberation of oxygen, yielding a solution which behaves like a mixture of zinc sulphate and hydrogen peroxide. The thermal disturbances at 15' are : Zn30,,2H,O sol. + 3H,SO, diss. develops + 16.04 x 3 Cal. Zn305,3H20 7, +3H,SO4 n ,, + 15-49x 3 ,, Zn407,4H,O 2, +4H,SO, 91 ,, + 14.86 x 4 ,, Zn0,,2H20 ,, +H2804 ,) ,, + 14.86 If the compounds are regarded as true peroxides, all their heats of formation are largely endothermic, which scarcely agrees with their marked stability, but if they are compounds of zinc oxide with hydrogen peroxide, their heats of formation in the solid state from zinc oxide and liquid hydrogen peroxide are Zn3O3,2H2O, sol. + 12.29 x 2 or + 8.19 x 3 ;Zn,0,,2H20,,H,0 + 12.24 x 2 or + S.16 x 3 ; Zn,04,3H20,,H,0 + 11.96 x 3 or + S.97 x 4, and Zn(OH),,H,O, + 4.87. It is noteworthy that all tbe compounds contain at least asmanymols. of water as there are atoms of active oxygen, C. H. B. Precipitation of the Chlorides and Bromides of Cadmium, Mercury, and Tin by Sulphuric Acid. By GEORGESVIARD (Compt. rend., 1902, 135, 242-244).--Cadmium chloride can be

Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. almost completely precipitated by adding an excess of sulphuric acid to the aqueous solution. The chloride is slightly attacked by the acid in the cold, Depending on the amount of sulphuric acid used, the cadmium chloride separates as dihydrate or monohydrate. Cadmium bromide is precipitated in the anhydrous form by an excess of sulphuric acid ; it is not attacked in the cold by the acid. Mercuric chloride. and bromide and stannous chloride and bromide are precipitated by an excess of sulphuric acid. J. McC. Toning Solutions containing Lead Thionates. By AUGUSTE LUMIBREand LOUISLUMIBRE and ALPHONSESEYEWETZ (Bull. Xoc. Chirn., 1902, [iii], 27, 792-797. Compare this vol., ii, 319).- The authors find that a toning-fixing solution of lead pentathionate and sodium thiosulphate yields results comparable with those obtained with a gold solution. On adding a quantity of gold equal to that contained in the ordinary toning-fixing solution, the tones obtained with a chlorocitrate paper are blacker and fresher than with the ordinary solution. Sulphur forms part of the toned image. The authors have also tried other salts of lead, especially the various thionates, but the best results are given by the pentathionate. The solutions are, however, unstable and in course of time give a deposit View Article Online

INORGANIC CHEMISTRY. 6 07

which appears to consist of sulphur, lead thiosulphate, and lead dithionate. A. F. Thallic Alu-m. By AUGUSTOPICCINI and V. FORTINI(Zeit. anovg. Chem., 1902, 31, 451-453. Compare Locke, this vol., ii, 497).-From thallic sulphate, the following double salts have been prepared : Tl,(S04),,R,S0,,8H20 where R = NH,,. K, and Rb. The rubidium salt very easily loses water. Since indium ammonium alum passes at 36’ into a double salt with S mols. of water, it seems probable that at some lower temperature the above thallic salts in contact with water would be transformed into the alums. Mixed crystals of ammonium alum with some of the aluminium replaced by thallium have been obtained. On sowing a supersaturated solution of ammonium alum with ammonium thallic sulphate, crystals of A12(S04)3,(NH,),S0,,8H20separate. Hence the octahydrated form of the double sulphates appears to be common to the salts derived from the three elements of the aluminium family, the stability- of the compounds increasing with the atomic weight of the metal. J. McC. Cuprous Compounds. 11. By GUIDO BODLANDERand 0. STORBECK(Zeit. anorg. Chem., 1902,31, 458-476. Compare this vol., ii, 502).-In attempting to determine the solubility of cuprous bromide it has been found that in water it partially decomposes into cupric bromide and copper. From the equilibrium relationships between cuprous ions, cupric ions, and metallic copper, it has been proved that the cuprous ion is mon:\tomic. Cuprous bromide is easily soluble in a solution of potassium bromide; in a dilute solution of a bromide, the complex ion CuBr,’ is present, whilst in more concentrated solution the complex ion is CuBr;. The discharge potential of cuprous

Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. ions is - 0.454 volt. The equilibrium relationships between cuprous iodide, cupric iodide, and iodine show that reaction occurs according to the equation: 2cu**+ 21‘ = 2cu*+ I,. The solubility products of the cuprous haloids are : CuC1, 1.2 x ; CuBr, 4.15 x and CuI, 5.06 x This is in agreement with Bodlander’s rule (Abstr., 1898, ii, 554) that the solubility decreases with diminishing discharge potential of the ions, In confirmation of Abegg and Eodlander’s rule (Abstr., 1899, ii, 542), it is found that the tendency towards the formation of complex ions increases as the decomposition tension or electro-affinity diminishes. Of the complex ions of the type CuX,’, that containing iodine is the mosi stable and that with chlorine the least. J. McC.

Anhydrous Ammonio-cupric Chlorides : Cuprammonio- radicles. By ALBERTBOUZAT (Compt. revhd., 1902,135,292-295).-The compound CuC12,6NH3is obtained by the action of liquefied ammonia on cupric chloride previously saturated with ammonia gas. It is a pale blue solid insoluble in liquefied ammonia, but soluble in water. It gradually dissociates, yielding the compound CuC12,4NH,, which has not previously been isolated, and its dissociation pressure is equal to atmospheric 41-2 View Article Online

608 ABSTRACTS OF CHEMICAL PAPERS.

pressure at about 90". The compound CuC1,,4NH3 also readily dissociates, yielding the compound CuC1,,2NH3, the dissociation pressure being equal to that of the atmosphere at about 140'. The heats of formation were determined by dissolving the compounds in (a)excess of ammonia solution, (b) excess of acid. CuCl, sol. + 2NH, gas = CuC1,,2NH3 sol. develops + 45.5 Cal. CuCl, ,, +4NH3 ,, =CuC12,4NH3 91 +72*06 ,, CUCI, 9, + 6NH3 9, = CuCl,,GNH3 99 +94'3 7) The heats of formation diminish and the dissociation pressure increases with an increase in the proportion of ammonia, and the value of the ratio Q/T, where Y' is the absolute temperature of dissociation at atmospheric pressure and Q is the heat of combination per mol. of ammonia, agrees with that found by Matignon in the case of other ammonio-chlorides. Cu sol. + 2NH3gas + 2HCl gas = Cu(NH3j,CI2 sol. + H, gas develops +52.9 Gal. Cu sol. + 4NH3gas + 2HC1 gas = Cu(NH3),C1, sol. + H, gas develops + 79.5 Cal. Cu sol. + 6NH3 gas t 2HCl gas = CU(NH,)~CI,sol. + H, gas develops + 101.8 Cal. C. H. B. [Density of Cuprous Iodide.] A Correction. By WALTHBRESPRING (Kec. trav. chim., 1902, 21, 294. Compare Abstr., 1901, ii, 451)- The molecular volume of cuprous iodide is not 34.73 but 32-72, The mol. volume, 33.61, is rather greater than that derived from the sum of the elements, namely, 32.72, but much smaller than 43.08 which is given by the density obtained by Schiff. The formation of cuprous iodide, therefore, probably takes place with expansion, but not to the extent of justifying any definite conclusion with regard to the decomposition of the substance by compression. A. F.

Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. Pasty Condition assumed by Aluminium in the Neighbour- hood of its Melting Point, and the Application of this Property to the Division of the Metal. By ALBERTGRANGER (BUZZ. Xoc. Chim., 1902, [iii], 27, 789--790).-When aluminium is heated to a temperature of about 600°, its tenacity and hardness become greatly modified, the metal assumes a grained structure, and can be easily broken. On heating to a still higher temperature, the metal can be cut with a knife or even crushed in a mortar. A. F. Dialysis Experiments with Metallic Hydroxides and Sulphides. By W. HERZ(Zeit. anorg. Chem., 1902, 31, 464-457). -When an alkaline solution of a.luminium, lead, or stannous hydroxide is placed in a dialyser, no precipitate is formed on the parchment and the metallic hydroxide easily passes through. With similar solutions of beryllium and zinc hydroxides, the colloidal substance does not diffuse so readily and there is aprecipitation of the hydroxide on the membrane; with chromium hydroxide, there is no diffusion. This is in agreement with Hantzsch's view (this vol., ii, 395) that aluminium, lead, and stannous hydroxides are acids, beryllium and zinc hydroxides are weak acids, and chromium hydroxide has no acid properties. View Article Online

INORGANIC CHEMISTRY. 600

When the brown solution obtained by dissolving nickel sulphide in ammonium sulphide is subjected to dialysis, the nickel partially diffuses but there is a large deposit of nickel"su1phide on the membrane. This shows that the solution is not a colloidal one in the ordinarily accepted interpretation of that term. J. McC. Constitution of the Compounds of Chromium. 11. By GREGOIREN. WYROUBOFF(Bull. h'oc. Chim., 1902, [iii], 27, 719-733. Compare this vol., ii, 56.5)-When an aqueous solution of sulphochromic acid is heated, a coagulum is formed which has the composi- tion of chromium suZphochromate, [Cr,O,( OH),( SO,),O,( OH),] Cr2(OH),, and is identical with that obtained by precipitating a violet salt of chromium in the cold with sulphochromic acid. If this is maintained for some time in contact with boiling water, it becomes hydrated, dissolves slowly, and finally passes entirely into n solution of the green sul phate. Chromium sulphochromate, when heated at 120', becomes soluble in water and the solution yields insoluble precipitates with metallic salts, chromosulphochromates being formed. These the author considers as ethers of the green sulphate in which two hydroxyl radicles have been replaced by sulphochromic acid. On adding hydrochloric acid to a solution of chromium sulphochromate, chvomosuZphochromic acid, [Cr,02(OH),(S02),0,,Cr20(OH)2(S02)3(OH)6](~OH)2,is precipitated as a dark green, gelatinous mass which dissolves in water, yielding an opalescent solution, On adding 2 mols. of sulphuric acid and a little water to 1 mol. of chromium sulphochromate, evaporating on the water-bath, and heating for some hours at 120'. chromodisulphociiro~nic

chromic acid, chromium sulphochromate yields a chromosulphodichrom- ate.

Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. If chromium sulphate is heated with an excess of sulphuric acid to a temperature not exceeding 150°, a clear green, gelatinous precipitate of sulphochromic acid is formed; on continuing the heating and at the same time allowing the temperature to rise, the green precipitate gradually changes into a heavy, greyish-yellow powder, soluble in water, yielding a milky, strongly acid solution. The same substance is obtained by heating sulphochromic acid for some time at 250°, and is the first anhydride of a polymeride of chromosulphochromic acid. The author also points out that although sulphochromic acid forms insoluble compounds with the metals, it does not give precipitates with all the salts of the metals. Thus, it gives a precipitate with a solution of mercuric nitrate or acetate, but not with mercuric bromide. The author explains this by saying that the last-named salt is an anhydride and not a normal salt. The author also gives details as to the method employed in the analysis of the compounds described. A. F. Colour Reaction of Uranium Salts with Hydrogen Per- oxide. By JULESF. ALOY(Bull. Xoc. Chim., 1902, [iii], 27,734-735). -On adding to the solution of any uranium compound a little hydrogen peroxide and then potassitlm carbonate, either solid or in very con- View Article Online

610 ABSTRACTS OF CHEMICAL PAPERS,

centrated solution, a fine red coloration is developed; on adding alcohol, the red compound is precipitated. This reaction may also be made use of for the detection of hydrogen peroxide, The red compound is very unstable, but the author has obtained apparently crys- talline compounds of uranium by treating the solution with methyl instead of ethyl alcohol. A. F. Vanadium Silicide. By HENRIMOISSAN and HOLT(Compt. rend., 1902, 135, 78-81).--Vanadium silicide, VSi,, is obtained by heating an intimate mixture of vanadium trioxide with a little more than five times its weight of silicon for about 2 minutes in an electric furnace with a current of 50 volts and 1000 amperes, and treating the residue successively with potassium hydroxide solution and strong nitric or sulphuric acid. It can also be obtained by reducing a mixture of silicon and vanadium trioxide with magnesium, It forms brilliant prisms which have a metallic lustre and a sp. gr. of 4.42, scratch glass, and melt and volatilise in the electric furnace. Alkalis and acids, with the exception of hydrofluoric acid, have no action on it, but it burns in fluorine, chlorine, or bromine when heated. Iodine vapour, oxygen, sulphur, and hydrogen sulphide attack it very slowly at the melting point of glass, but hydrogen chloride converts it into silicochloroform and vanadium chloride. Fused alkali hydroxides decompose the silicide; the action of fused metals depends on whether they combine more readily with silicon or with vanadium. Copper, for -example, yields copper silicide and a copper vanadium alloy, C. H. B. Liquid Hydrosol of Gold. By ALEXANDERGUTBIER (Zeit. anorg. Chem., 1902, 31, 448--450).-A pseudo-solution of gold is obtained by reducing a very dilute solution of auric chloride with hydrazine hydrate in the cold. When the reduction is properly carried out, the Published on 01 January 1902. Downloaded 31/10/2014 10:47:34. solution is blue and keeps well, but when an excess of hydrazine is added the gold quickly separates. By this reduction process, pseudo-solutions of silver, copper, lead, selenium, and tellurium can also be prepared. J. McC.