摘要:

AbstractMethods are given for the preparation of 22 organotin compounds of the type R3SnX, including 16 not previously described. The fungicidal properties of these compounds were described in Part III of this series.

ISSN:0021-8871    

DOI:10.1002/jctb.5010060201

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe preparation of a number of unsymmetrical tri‐n‐alkyltin acetates is described.From the antifungal test results of these compounds it appears that a single rule governs the activity of both symmetrical and unsymmetrical tri‐n‐alkyltin acetates, namely that it is the total number of carbon atoms present in the alkyl groups, rather than the nature of the groups, which governs the fungitoxicity of the compounds; this is greatest for a total of 9–12 car

ISSN:0021-8871    

DOI:10.1002/jctb.5010060202

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe influence of humidity and temperature on the stability of bleaching powder has been investigated. At 40°, the available chlorine content of a tropical bleaching powder was reduced by half in 51 weeks at 0% relative humidity but in only 5 weeks at 100% relative humidity. At low humidities the deterioration produced by temperature was not excessive up to about 36°, but beyond 40° temperature contributed significantly to instability even at 0% relative humidity. Empirical equations have been developed relating stability to relative humidity, and amount of water absorbed to time of exposu

ISSN:0021-8871    

DOI:10.1002/jctb.5010060203

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe chemical composition of alkali metal sulphate‐vanadium oxide mixtures in equilibrium with SO3‐SO2‐air mixtures has been investigated. These gas mixtures were prepared from a 5% SO2–95% air mixture, the ratio of SO2to SO3being maintained at the equilibrium value corresponding to the temperature of each run. Experiments have been carried out with mixtures of V2O3and one alkali metal sulphate (Na, K, Rb, or Cs) in the temperature range 380–600°.In the temperature range 440–600° a liquid is produced, consisting of vanadium compounds dissolved in an alkali pyrosulphate‐sulphate mixture. The melting point of the mixture formed decreases with increasing atomic weight of alkali metal used. The weight increases observed with an alkali sulphate/V2O6molecular ratio of 2.5/1 suggest the formation of normal pyrosulphate, M2S2O7, and VOSO4. With the Rb2SO4and Cs2SO4mixtures there is also evidence for the part formation of a higher sulphate, M2S3O10. The extent of reduction of the V2O5is lower in the presence of alkali metals of higher atomic weight. Thus potassium is more effective in stabilizing the vanadium in the pentavalent state than is sodium, and caesium is even better. This may account for the preference for the potassium salt over the sodium salt as a promoter in comme

ISSN:0021-8871    

DOI:10.1002/jctb.5010060204

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractVapour‐liquid equilibrium data for the system carbon tetrachloride‐benzene have been determined under isobaric conditions at 760 mm. Hg pressure and isothermal conditions at 40°, using an improved equilibrium still. The experimental results are found to be thermodynamically consistent. An azeotropic mixture is predicted to exist at pressures above 1800 mm

ISSN:0021-8871    

DOI:10.1002/jctb.5010060205

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractGelatin layers show minimum swelling when the temperature of the layer during drying is about 35°. When dried at a higher temperature, the layer is ‘so‐like’ and bonding does not occur until the layer is swollen or conditioned at a high relative humidity.Sol‐like layers of non‐de‐ionised gelatin when swollen in distilled water swell rapidly to a maximum value and then contract to a final value. De‐ionized sol‐like layers swell straight to this final value. The overshoot with the non‐de‐ionized layers is believed to be due to osmotic forces within the layers, which disappear when the salts are washed out.When conditioned in an atmosphere of high relative humidity, all layers afterwards show a reduced swell. The reduction is very large and very rapid for sol‐like layers. The results are explained by assuming that bonds formed during setting and drying are under no strain at the time of their formation and will tend to resist any compressive or tensile strains caused by drying or by increased swelling, respectively. The number and the strength of the bonds will be controlled by

ISSN:0021-8871    

DOI:10.1002/jctb.5010060206

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe effect of (1) the molecular ratio Na2CO3/CuSO4, (2) concentration of the reacting solutions, (3) mode of agitation during precipitation, and (4) ageing of the precipitate on the chemical composition and physical properties of the products from mixing aqueous solutions of copper sulphate and sodium carbonate was investigated. For products of definite chemical composition and desirable physical properties, the recommended precipitation conditions are: molecular ratio Na2CO3/CuSO4, 1.1:1; concentration of reacting solutions, approximately 1.0 molar; mild stirring; and sufficient time must be allowed for the precipitate to transform from blue gelatinous to green crystalline form. The CuO/CO2ratio in the precipitates thus obtained correspond with that of malachite.

ISSN:0021-8871    

DOI:10.1002/jctb.5010060207

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010060209

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY