摘要:

AbstractCorresponding to views developed in the first paper a formula is given, which roughly estimates the total energy of interaction between two colloidal particles as a function of their distance apart: this formula contains the particle charge E and the electrolyte concentration c as two independent parameters.The properties of a colloidal system are discussed for arbitrary values of E and c. The E‐c plane obtained by plotting E and c as abscis and ordinate in a rectangular system of axis is found to be split up in different portions; in one region a sol is stable, in another it is flocculated, while in intermediate regions more complicated conditions prevail.A physical change in the sol is represented by a simultaneous variation of E and c, that is by a curve in the E‐c plane. With the aid of such curves a variety of phenomena viz. peptisation, reversible and irreversible flocculation, and thixotropy are discussed in a clear and simple

ISSN:0165-0513    

DOI:10.1002/recl.19370560102

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractEs wurde die Farbenwiedergabe beim Photographieren bei Neonlicht und Mischungen desselben mit Quecksilberlicht auf verschiedenem Negativmaterial untersucht.

ISSN:0165-0513    

DOI:10.1002/recl.19370560103

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractAuf Grund der Stellung im Periodischen System war die Bildung von Mischkrystallen zwischen SrF2und LaF3zu erwarten. Die röntgenographische Untersuchung ergab tatsächlich, dass bis zu einem Gehalt von ungefähr 30 Molprozent LaF3Mischkrystalle des CaF2‐Typus vorliegen. Durch Dichtemessungen konnte erwiesen werden, dass die isomorphe Vertretung des zweiwertigen Strontiumions durch das dreiwertige Lanthanion unter gleichzeitigem Einbau eines Fluorions stattfindet. Die hier gefundene Vertretung unter Füllung vakanter Gitterorte war von Goldschmidt für das analoge System CaF2‐YF3schon vermute

ISSN:0165-0513    

DOI:10.1002/recl.19370560104

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractAn X‐ray analysis was carried out of Na‐ Cs‐ and TIBF4 which proved to be isomorphous with the corresponding Perchlorates. The compound BF3. NaOH, isomorphous with NaBF4, should be formulated as the sodium salt of monohydroxyfluoboric acid; the hydroniumsalt of the same acid (BF3. 2H2O) formed the subject of a previous publication.From the dissociation pressure, the heat of dissociation of NaBF4and NaOH. BF3was determined. The relative stability of both compounds was disc

ISSN:0165-0513    

DOI:10.1002/recl.19370560105

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractIn this communication a simple method will be developed for approximating the most economical way in which separation of raw material into final products may take place in a gradual continuous process of separation or combination of such processes, wherein the principle of countercurrent is applied.

ISSN:0165-0513    

DOI:10.1002/recl.19370560106

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractDie Potentiale an einer blanken und einer platinierten Platinanode während der Elektrolyse einer Natriumazidlösung und der Einfluss von Kaliumrhodanid auf diese Potentiale wurden bestimmt. Kaliumrhodanid macht die Potentiale weniger positiv. Dies ist im Einklang mit der Tatsache, dass Jod nur im Gegenwart von Kaliumrhodanid imstande ist aus Natriumazidlösungen Stickstoff zu entwickeln.Weiter zeigte sich, dass der Stickstoff, welcher in statu nascendi bei Elektrolyse einer Natriumazidlösung entsteht, in Gegenwart von Phenol, Spuren eines Isonitrils bil

ISSN:0165-0513    

DOI:10.1002/recl.19370560107

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractIntroduction. In previous communications the results of polymerisation experiments carried out with several unsaturated hydrocarbons were describedA general survey is given in Trans. Faraday Soc., “A general discussion on polymerisation and condensation”, 37, 251 (1936).H. I. Waterman, J. J. Leendertse and W. A. A. Blanche Koelensmid, Rec. trav. chim. 55, 7 (1936).H. I. Waterman, J. J. Leendertse and J. Ph. Makkink, J. Inst. Petroleum Tech. 22. 333 (1936).In the present paper the results of the polymerisation of tetrahydro‐naphthalene with aluminium chloride as a catalyst will be described. The nature of the reaction products of the polymerisation was investigated by using the specific refractivity‐molecular weight methodJ. C. Vlugter, H. I. Waterman and H. A. van Westen, J. Inst. Petroleum Tech. 21, 661 (1935). see also J. C. Vlugter, Thesis Delft 1932..Though the reaction products that have been obtained by the polymerisation of tetrahydronaphthalene at 50°C with aluminium chloride as a catalyst are strongly cyclic, their nature can only partly be explained by the supposition that the reaction during the polymerisation experiment is a “theoretical polymerisation”, in which the molecular weight regularly increases, without any ring opening or ring formation.It has been proved in analogy with the work of SchroeterG. Schroeter, Ber. 57, 1990 (1924).that some ring opening occurred during the polymerisation. Also a rather important quantity of a solid, crystalline compound which contained 3 rings per molecule has been separated from the reaction products.The production of gases has not been observed in the po

ISSN:0165-0513    

DOI:10.1002/recl.19370560108

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractThe chlorination of chlorobenzene vapour in the presence of pumice as a contact substance has been studied at 500°, 550° and 600°. The reaction proceeds violently; even when a large excess of chlorobenzene is used, carbon is formed, especially in the experiments at 550° and at 600°. Besides dichlorobenzenes a considerable quantity of higher chlorinated benzenes is formed; the yields of dichlorobenzenes are low. The mixture of dichlorobenzenes has been isolated from the reaction product and the proportions of isomerides has been determined by thermal analysis. The main product (50%‐60%) of the mixture of dichlorobenzenes formed within the range of 500–600°, ismeta‐dichlorobenzene.Although the chlorination of chlorobenzene at high temperatures is not suitable for an exact quantitative investigation, it is proved in this paper, that this substitution reaction belongs to themeta typeat 500–600° in the presence of pumice as a con

ISSN:0165-0513    

DOI:10.1002/recl.19370560109

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractThe following systems were investigated at a pressure of 60 cm Hg as well as at lower pressures: CH4O2CO2, CH4O2SO2, CH4N2OCO2CH4N2OSO2, CH4CH3ClO2, CH4O2N2O, CH3ClN2O in continuation of an investigation of the explosivity of H2O2N2mixtures published in this journal.The phenomena which were exhibited therein were described. It was found that at low pressure the wall of the reaction vessel becomes catalytically active, if explosions take place in it repeatedly. The change of pressure resulting from an explosive reaction was

ISSN:0165-0513    

DOI:10.1002/recl.19370560110

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY

摘要:

AbstractThe literature, especially that since 1930, gives extensive discussions on the nature of a reaction which proceeds explosively. If one wishes to investigate the function which the pressure and change of concentration perform in determining the position of the limits one arrives, after a fairly complicated deduction, at formulae which reproduce these influences fairly simplySee C. N. Hinshelwood and A. T. Robinson, The Reaction between Hydrogen and Oxygen, 1932, p. 59. Frost and Alyea, J. Am. Chem. Soc. 55, 3227 (1933). Storch and Montgomery, J. ibid. 56, 2644 (1934). It is however possible to describe these limits fairly accurately by functions deduced in a very simple way as is shown à propos of experiments described in a previous article in this journal. That holds also for explosions which undoubtedly exhibit a complicated reaction mechanism

ISSN:0165-0513    

DOI:10.1002/recl.19370560111

出版商:WILEY‐VCH Verlag    

年代:1937

数据来源: WILEY