Inorganic Chemistry. 477
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View Article Online / Journal Homepage / Table of Contents for this issue INORGANIC CHEMISTRY. 477 Inorganic Chemistry. Decomposition of Hydrogen Peroxide under the Influence of Radium Bromide. HENRYJ. H. FENTON(Proc. Camb. Phil. SOC., 1904, 12, 424--426).-The velocity coeficient for the decomposition of hydrogen 'peroxide in paraffin-coated vessels, calculated from the expression for a unimolecular reaction, gradually increases as the peroxide concentration diminishes. In glass vessels the decomposition velocity is irregular at first, but becomes approximately constant after a few days. The velocity of decomposition, either in glass or paraffin- Published on 01 January 1904. Downloaded 30/10/2014 10:59:06. coated vessels, is approximately doubled under the influence of radium bromide. J. C. P. Boiling Oxygen. A. RESTELMEYER(Ann. Physik, 1904, [iv], 14, 87-98).-A study of the extent of possible superheating in boiling oxygen. The results obtained make it probable that previous de- terminations of the boiling point of oxygen, in which the thermometer was immersed in the liquid, are a few tenths of a degree too high. On the other hand, the author's results are in harmony with the determinations oE Travers, Senter, and Jaquerod (Abstr., 1903, ii, 9), who used a statical method. J. C. P. The Melting Points of Oxygen and Nitrogen. TADEUSZ ESTREICHER(BUZZ. Acad. Xci. Cracow, 1903, 831--844).-The melting point of oxygen was determined with a helium thermometer; it was found to be approximately -227O. The vapour pressures of melting oxygen, nitrogen, and atmospheric nitrogen were determined by solidifying these gases in a closed vessel connected with a mercury manometer. When the solids were allowed to melt slowly, the pressure, at first zero, gradually rose to a value which remained constant VOL. LXXLXVI.ii. 34 View Article Online 478 ABSTRACTS OF CHEMICAL PAPERS, until complete liquefaction had taken place. In this way, the vapour pressure of melting oxygen was shown to be 0.9 mm., that of melting nitrogen 93.5 mm., and atmospheric nitrogen 90.2 mm. The vapour pressures of nitrogen at temperatures near the melting point have already been determined (Fischer and Alt, Miinchener Akad., 1902, 209); with the aid of Ramsay and Young's method, these values may be used to calculate the temperatiire of nitrogen corresponding with any vapour pressure. Accordingly, the temperature of nitrogen which exerts a pressure of 93.5 millimetres is found to be -210.24' (this figure represents the melting point of pure nitrogen); similarly, atmospheric nitrogen is shown to melt at -210.47'. The difference between the two values, 0.23', is the lowering in the freezing point of liquid nitrogen which is exerted by the argon in atmospheric nitrogen (1.70 grams per 100 grams of nitrogen). In this way, the author calculates the molecular depression of freezing point of liquid nitrogen and finds it to be 5.39, whence the latent heat of fusion equals 14-49 cal. or 60.44 Joules. s. s. Heat of Vaporisation of Oxygen and Sulphur Dioxide. TADEUSZESTREICHER (Bull. Acccd. Xci. Cracow, 1904,183-196).-The method consists in measuring the volume of gas liberated by a known amount of heat which is generated in a platinum resistance wire im- mersed in the liquid. The quantity of electricity passing through the resistance during the experiment was determined by means of a silver voltameter, and t,he difference of potential between the ends of the wire was measured with a standardised voltameter, In measuring the volume of the gas liberated, a correction must be applied for the normal evaporation which takes place without heating the platinum wire. The sulphur dioxide employed was prepared by dropping concentrated sulphuric acid into a strong solution of sodium Published on 01 January 1904. Downloaded 30/10/2014 10:59:06. sulphite. The heat of vaporisation oE liquid sulphur dioxide at its boiling point (10.1') was found to be 96.2 cal. per gram; a value which agrees very closely with that obtained by Mathias (Abstr., 1888, 773), 96.19 at the same temperature. The oxygen was prepared from potassium chlorate, and was washed with potassium hydroxide before use. The latent heat of vaporisation of liquid oxygen is 58.0 cal. per gram. s. s. OzoneApparatus. W. ELWORTHY(Chem. Centy., 1904,i, 1313-1314; from Electrochem. Zeit., 11, 1--5).-1n the apparatus described, the silent discharge takes place between spirals of aluminium. The air does not require to be cooled by water, the temperature being kept sufficiently low by employing a rapid stream which is made to pass twice through the field of discharge by means of concentric glass tubes. The air is not specially dried. The apparatus comprises a battery of 10 tubes together with other accessories. By employing an alternating current at 130 volts raised to 11,000-12,000 volts by means of a transformer, 70 grams of ozone per kilowatt-hour are obtained, and the concentration of the ozone reaches 0.4-0.5 gram per cubic metre. E. W. W. View Article Online INORGANIC CHEMISTRY. 479 Formation of Ozone at High Temperatures. J. K. CLEMENT (Ann. Phpik, 1904, [ir], 14, 334-353).--8ince the stability of endothermic substances increases as the temperature rises, it is to be expected that at high temperatures oxygen is converted, partly at least, into ozone. Attempts to realise this, in which oxygen was rapidly passed over the electrolytic glow body of a Nernst lamp, were unsuccessful, and no ozone could be detected. So long as traces of nitrogen were present in the oxygen, nitric oxide was produced, a, substance the behaviour of which in small concentrations is very similar to that of ozone. The formation of ozone at high temperatures has been recorded by earlier workers, but it is probable that the reactions observed were those of nitric oxide, since no care was taken to exclude nitrogen. Ozone is certainly produced by an electric spark, but this result may be attributed to the action of ultraviolet light. The author has further studied the rate of decomposition of ozone at higher temperatures. A current of ozonised oxygen, obtained by electrolysis of sulphuric acid, was passed through n vessel kept at a constant temperature, the amounts of ozone before and after the passage of the gas being determined by absorption in potassium iodide and subsequent titration with thiosulphate. The reaction is bimole- cular, as found also by Warburg (Abstr., 1902, ii, 130), and van't Hoff's equation for the change of velocity coefficient with temperature represents the experimental results very satisfactorily. It may thus be shown that at 1000" the percentage of ozone in oxygen would fall from 1.0 to 0.001 in 0.0007 second. Hence, even if ozone is formed in quantity at a temperature of about 2200", it must be decomposed during even the most rapid cooling. J. C. P. Action of Sulphuryl Chloride on Metallic Oxides. E. SPELTA (Gaxxetta, 1904, 34, i, 262-267).-Sulphuryl chloride and lead oxide do not react, even when heated together at 140-150" in a sealed tube Published on 01 January 1904. Downloaded 30/10/2014 10:59:06. for several hours. With lead peroxide, however, sulphuryl chloride readily reacts, sometimes with explosive violence, according to the following equation : 2Pb0, + SO,Cl, = PbSO, + PbC1, + 0,. If the sulphuryl chloride is in slight excess, and the mixture becomes heated above its boiling point, chlorine is also evolved. With mercuric oxide prepared in the dry way, sulphuryl chloride does not react even on prolonged heating. With yellow mercuric oxide (2 mols.), however, sulphuryl chloride (1 mol.) readily reacts at 150" in a closed tube: 2Hg0 + SO,CI, = HgSO, + HgCl,. If the sulphuryl chloride is in excess, sulphur trioxide is also formed, ac- cording to the equation : HgO + SO,Cl, = HgCI, + SO,. Prom these reactions it is seen that sulphuryl chloride, which is readily formed from sulphur dioxide and chlorine, is also readily resolved into these components, the change being hence a reversible one, The chlorinating action of sulphuryl chloride must be due to a slightly stable linking between the sulphur dioxide and chlorine, a linking which must have a special form, since its rupture takes place preferably in presence of elements having an electro-positive character. T. H. P. 34-2 View Article Online 4so ABSTRACTS OF CHEMICAL PAPERS. Electrolytic Oxidation of Sulphites and Electrochemical Formation of Dithionate. ALFREDFRIESSNER (Zed. Elektrochem., 1904, 10, 265-289).-1n neutral or alkaline solutions, the sulphites of the alkali metals are not reduced at the cathode ; at the anode they are oxidised, partly to sulphate, partly to dithionate, 2Na,SO, + 0 + H,O = Na,S,O, + 2NaOH. Dithionate is not formed under any con- ditions when the solution is acid, the only product formed at the anode being sulpbate ;at the cathode, however, hyposulphite and thio- sulphate are produced. The formation of dithionate in neutral or alkaline polutions is found to be conditioned by the potential of the anode. By polarising the (platinum) anode anodically in a solution of sodium hydroxide before use, the formation of dithionate is insured, whereas a cathodically polarised or a depolarised electrode. gives no dithionate. These remarks apply to platinised platinum anodes : a smooth platinum anode soon becomes polarised in the sulphite solu- tion itself sufficiently to produce dithionate even if it is initially depolarised. The formation of dithionate is favoured by a rise of temperature to 60-70'; it is practically unaffected by the concen- tration of the sulphite solution. The latter fact together with the fact that it is not formed in acid solutions shows that the dithionate is produced from SO," ions, and the following equation is given as representing the elect,rical reaction, 2S0," + 20H' + 2H' + 2F= S,O," + 2H,O.