摘要:

AbstractThe solubility‐product constant of LaF,(s) was obtained by potentiometric titration of sodium fluoride with lanthanum perchlorate in sodium perchlorate solutions of various ionic strengths. The limiting value ofpKs.pwere found to be 17.65 and 17.95 at 20° and 25°C, respectively. Thermodynamic calculation from these values givesδG°=‐102.46 kJmol−1,δH°= 100.40 kJmol−1andδS°= 680.40JK−1for the reaction, La+3(aq)+3F‐(aq)=LaF,(s), andδG°=‐1613.8kJmol‐1, δH1° =‐1594.0kJmol−1andS° =433.1JK−1mol−1for the formation of LaF2,(s) at 25°C. The mean activity coefficients and solubilities of LaF2,(s) in NaCIO4solution at various i

ISSN:0009-4536    

DOI:10.1002/jccs.197400001

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractForce constants of planar symmetricXYntype molecules in the Cartesian space have been derived in terms of the vibrational frequencies. The force constants and normal coordinates of some planarXY3molecules with available isotoptic data are worked out. Further study of infrared absorption spectra of square planarXY4complex ions will be needed for the present normal coordinate analysis.

ISSN:0009-4536    

DOI:10.1002/jccs.197400002

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractMössbauer spectra of K4Fe(CN)6and K4Fe(CN)63H2O, observed 3 weeks after irradiation, did not differ from the unirradiated samples, which implied that there was no change in oxidation state of iron. The fresh aqueous solutions of these irradiated samples also did not show any change in the oxidation state. Fe(OH)3separated in chemical treatment was time dependent and was further influenced by the chemical reagents

ISSN:0009-4536    

DOI:10.1002/jccs.197400003

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractMössbauer spectra of irradiated K1Fe(CN)6, observed 3 weeks after irradiation, showed that 3% of iron was converted to Fe(CN)64−, while chemical analysis performed 100 hours after irradiation showed 18% was reduced to Fe(CN)64−, Prussian blue was isolated in the chemical analysis, but not observed in the Mössbauer spectra. The Prussian blue formation was found to be time depe

ISSN:0009-4536    

DOI:10.1002/jccs.197400004

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThermometric titrations of lanthanum perchlorate, titanium (III)‐chloride, uranium (IV)‐sulfate, and uranyl sulfate with EDTA solutions were carried out by using a Keithley nanovoltmeter with a rhodium‐platinum thermocouple at 25°±0.01°. The formation of LaY−, TiY−, U(IV)Y and UO2HY−ions was confirmed. The heat of reaction for the system, Ti(III)+H2Y2−= TiY−+2H+, was given byδH1= 1.933‐1.422×10m+2.056×104m(in cal) and the limiting value was evaluated to beδH

ISSN:0009-4536    

DOI:10.1002/jccs.197400005

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractOxidations of α‐cadinol,T‐cadinol, T‐muurolol and δ‐cadinol with SeO3gave corresponding ketols and diols. Reductions of the ketols with NaBH4gave epidiols. NMR data of these sixteen compounds are

ISSN:0009-4536    

DOI:10.1002/jccs.197400006

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractA method using ninhydrin reagent for proteolytic activity measurement and kinetic studies with protein or modified protein as substrate was explored. As the reagent is specific for amino group, quantitative expression can be made with the number of peptide bonds cleaved. The sensitivity of the method made it possible for the determination of various kinetic parameters such as Km, Vmaxand Kcatwith the measurement of initial velocity. As an example, these quantities were determined for pancreas protease with casein andN,N‐dimethylcasein as substrates. This study made clear the possibility of using a common substrate of proteolytic enzymes for kinetic studies and a general reference for activity expression. By introducing the use of initial velocity in the kinetic studies of proteolysis with protein as the substrate, this study also makes clear that the kinetics of the enzymatic proteolysis very well fits the Michaelis‐Menten law instead of the Schütz

ISSN:0009-4536    

DOI:10.1002/jccs.197400007

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractEaethiol contents of 1, 5‐diphenyl 2, 4‐dithiobiuret (DP); 1, 5‐di‐p‐tolyl 2, 4‐dithiobiuret (DPT); 1‐phenyl 5‐p‐tolyl 2, 4‐dithiobiuret (PPT); 1‐phenyl 5‐o‐tolyl 2, 4‐dithiobivret (POT); and 1‐methyl 5‐p‐tolyl 2, 4‐dithiobiuret (MPT) have been studied by alkali titration method in methanol and by spectrophotometric method in different solvents of varying polarities, ranging from pyridine (Z, 64.0) to methanol (Z, 83.6). Free energy of tautomerisation has been calculated. The effect of substituents on the phenyl group on enethiol contents have been studied. It has been observed that temperature has no ef

ISSN:0009-4536    

DOI:10.1002/jccs.197400008

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThe reaction between gallium (III) and glycine thymol blue has been studied spectrophoptometrically in order to establish the optimum conditions for determining traces of gallium. The gallium (III) glycine thymol blue complex has an absorption maximum at 560nmagainst a reagent blank and is stable betweenpH 4.0 and 5.5. The complex has a composition 1 : 2 and a formation constant of 6.4×107under the conditions studied. Beer's law is obeyed upto 126μgof gallium. The net molar absorptivity has been found to be 11,000. The present method is very sensitive and rapid. Anions such as citrate and tartrate inhibit the colour development of the comple

ISSN:0009-4536    

DOI:10.1002/jccs.197400009

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractComplexation of 3‐nitroso‐4‐hydroxy‐5, 6‐benzocoumarin with iron (II) is used to detect iron in presence of various ions present in the scheme of semi‐micro qualitative analysis. The method finds application in detection of iron in alloys, inorganic salts and various pharmaceutic

ISSN:0009-4536    

DOI:10.1002/jccs.197400010

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY