摘要:

Abstract2:2‐Bis‐(p‐chlorophenyl)‐1:1:1‐trichlorocthanc reacts with hydroquinone and concentrated sulphuric acid at 100° to produce a wine‐red colour. The reaction has been studied and developed into a quantitative analytical method for the determination of DDT. The reaction is sufficiently specific to permit the determination of the purity of commercial samples of DDT with an accu

ISSN:0368-4075    

DOI:10.1002/jctb.5000660301

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe oxidative power of the ferricyanide‐carbonate reagent towards dextrose and maltose is decreased by the presence of sodium chloride and sodium acetate, in quantities such as would be present after the hydrolysis of starch by hydrochloric acid or by β‐amylase in the presence of an acetic acid‐sodium acetate buffer. The oxidative power of the reagent is lowered by exposure to diffuse daylight and possibly also by prolonged storage in th

ISSN:0368-4075    

DOI:10.1002/jctb.5000660302

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractTemperature surveys across the diameter of a wetted‐wall fractionating column operating on ethanol‐water mixtures have indicated the form of vapour composition distribution across the column; the assumption being made that the temperatures measured were the condensation temperatures of the vapour. The results illustrate the similarity between the processes of fractionation, uni‐directional diffusion and heat transfer. In fractionation, H.T.U. obtained by thermocouple “sampling”17, 18, and based on the mean vapour compositions are in close agreement with corresponding data obtained by sample‐withdra

ISSN:0368-4075    

DOI:10.1002/jctb.5000660303

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe dependence of the Height of B Transfer Unit upon the column operating characteristics and the physical properties of the mixtures distilled has been examined in experiments on two small packed columns in which carbon tetrachloride‐benzene and methyl‐cyclohexane‐toluene mixtures were distilled. Correlation of the experimental data by means of a dimensionless equation:– was not complete due to a vapour composition effect similar to that previously observed in experiments on wetted‐wal

ISSN:0368-4075    

DOI:10.1002/jctb.5000660304

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractIn Parts 1–5 of this paper1charts were given which showed the vapour pressures of ammonia and carbon dioxide over aqueous solutions at 20° and 40°. Measurements of the vapour pressure of ammonia have now been made at 90° in order to provide data for calculating the efficiency of ammonia st

ISSN:0368-4075    

DOI:10.1002/jctb.5000660305

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe application of polar concepts to the interpretation and systematisation of experimental observations in the field of organic chemistry has had such striking success and usefulness during the past 25 years that the concepts have become an integral part of organised chemical knowledge. Recent years, however, have seen the steady accumulation of experimental results which do not fit in the polar scheme and these may be rationally and consistently interpreted as resulting from the occurrence of apolar types of reaction in which the participants are short‐lived neutral entities (molecules or atoms) displaying free‐radical characteristics. On the apolar basis the author outlines a hypothetical correlation of a considerable array of experimental results with which he has been concerned—both as an immediate aid to making sense of what would otherwise seem to be unusually complicated and unintelligible, and with the hope that the views tentatively advanced will furnish suggestive starting points for future kinetic experiment

ISSN:0368-4075    

DOI:10.1002/jctb.5000660306

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractAn examination of the more available metallic pigments has been made with the object of preparing paints capable of protecting steel cathodically; for this to occur two conditions must be fulfilled:1The metallic pigment must be of a metal less noble than iron.2The pigment particles must be in metallic contact with each other and with the coated steel. It has been shown that whereas aluminium powder, zinc dust, and magnesium powder satisfy condition (i), only zinc dust fulfils condition (ii).

ISSN:0368-4075    

DOI:10.1002/jctb.5000660307

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractStudies in progress in this laboratory have demanded the quantitative recovery of unsaponifiable substances from a wide range of marine oils. A critical study of the recovery of different types of unsaponifiable matter from such oils by the Society of Public Analysts' method has therefore been made.

ISSN:0368-4075    

DOI:10.1002/jctb.5000660308

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe influence of discharge capacity, electrode shape and size, electrode material, temperature of the vapour‐air mixture, and resistance in the discharge circuit, on the ignitibility of a number of solvent vapour‐air mixtures has been examined. Ignition occurs most easily,i.e.at a minimum energy, when the capacity is low; when the electrodes are not points a minimum voltage is necessary for ignition no matter what it is the size of the capacitor, but with point electrodes the critical factor is the energy stored in the capaci

ISSN:0368-4075    

DOI:10.1002/jctb.5000660309

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractIt has already been found in several reactions that Friedel‐Crafts catalysts are only effective when traces of water are present. We have found that this does not apply to the polymerisation reaction ofiso‐butene with BF3and AlCl3under conditions where high‐molecular weight products are formed. On the other hand, some indications were found pointing to the fact that the reaction proceeds more slowly when working under dry conditions. The phenomena observed are explained in the most satisfactory way by accepting a polarising effect of the positive metal atom on the olefin. Some possible explanations are given for the phenomena found by Polanyi and co‐workers which indicate that presence of moisture can be important in certai

ISSN:0368-4075    

DOI:10.1002/jctb.5000660310

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY