摘要:

AbstractReaction rates for the alkaline hydrolysis of methyl‐, ethyl‐,n‐propyl‐ andn‐butyl acetates in the presence of 0.01Nsodium hydroxide solution at 15°, 20°, 25°, 30° and 35°C were followed directly by conductometric measurements of the reacting system. The energies and entropies of activation for these reactions

ISSN:0009-4536    

DOI:10.1002/jccs.196200011

出版商:WILEY‐VCH Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractPyrocatechol‐sulphonphthalein (abbreviated to PV) and its germanium complex were polarographically studied in an acetic acid‐acetate buffer at various pH's. A well‐defined reduction wave for PV withEranging from —0.46 to —0.73 volt (S.C.E.) was observed in the pH region 3.2—7.0 at 25°C. This wave corresponds to a one‐electron reduction which is nearly revrsible. By following theiavalues of PV at varying mole ratios of Ge(IV) to PV, the composition of the complex was deemed to consist of Ge(PV)2and the instability constants were found to be (3.1±0.4)×10−8at pH 5.0, (1.7±0.3)×10−8at pH 6.1 and (1.9±0.4) × 10−8at pH 6:5, respectively. A mthod for the computation of the instability consta

ISSN:0009-4536    

DOI:10.1002/jccs.196200012

出版商:WILEY‐VCH Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractThe complex formation between germanium and gallein (Pyrogallolphthalein) was polarographically studied in acetic acid‐acetate buffers at various pH's. The mole ratio of germanium to gallein was estimated as 1:2. The apparent instability constant of the complex was computed as (6.5 ± 0.2) ×10−2at pH 5.0 and (1.05 × 0.05) ×10−2at pH 6.0, respectively, while that corrected for pH effect was evaluated as (4.3±0.1) ×1

ISSN:0009-4536    

DOI:10.1002/jccs.196200013

出版商:WILEY‐VCH Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractPolarographic and amperometric methods for the determination of potassium by using sodium dipicrylaminate as the precipitating agent were investigated. Several methods for the location of the end point in the amperometric titration and the method for the calculation of the original concentration of potassium present in the test solution were discussed. In the amperometric titration, the sample solution was presaturated with potassium dipicrylaminate. A 0. 1Fsodium hydroxide solution was used as the supporting electolyte. The constant potential applied was —1.8voltvs. a Hg‐pool electrode and the temperature was 0—0.3°C. Advantages and disadvantages of the methods were discussed. The solubility of potassium dipicrylaminate and the solubility product of dipicrylamine at various temperatures were determined spectrophotometrically. A special type of filter bar used in the solubility and solubility product determinations was des

ISSN:0009-4536    

DOI:10.1002/jccs.196200014

出版商:WILEY‐VCH Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractThe reaction between ethyl γ‐bromocrotonate and disodiosuccinosuccinic ester has been investigted. The condensation product, on hydrolysis, gave a tetracarboxylic acid which, unlike other β‐ ketonic acids, was resistant to decarboxylation. This is discussed in connection with the decarboxylation of β‐ketonic acids in

ISSN:0009-4536    

DOI:10.1002/jccs.196200015

出版商:WILEY‐VCH Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractA further refinement in the evaluation of ϵ′ folding energy 13 presented. It is found that a correction termR3TT2/(a3—1) should be included into a previously derived equation, if ϵ′ is determined by stress‐temperature measurements at constant pressure and constant extended length. The results confirms quantitatively our previous estimation that when relative extension ratio is greater than 1.5, the correction term is n

ISSN:0009-4536    

DOI:10.1002/jccs.196200016

出版商:WILEY‐VCH Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractSome differences in physico‐chemical properties between the starch granules of Native Rice andPonlaiRice have been found; The protein content and amylose content of Native Rice starch are higher than that ofPonlaiRice. They exhibit different types of gelatinization curves. The effect of protein distribution and that of amylose content on the physical properties of rice starch granules has been discusse

ISSN:0009-4536    

DOI:10.1002/jccs.196200017

出版商:WILEY‐VCH Verlag    

年代:1962

数据来源: WILEY