THE MONO-OXALATO COMPLEXES OF IRON(III): PART I. EQUILIBRIA

1965 ◽  
Vol 43 (10) ◽  
pp. 2755-2762 ◽  
Author(s):  
R. F. Bauer ◽  
W. MacF. Smith
Keyword(s):  
Ionic Strength ◽  
Hydrogen Ion ◽  
Extinction Coefficients ◽  
Ion Concentrations ◽  
Oxalato Complexes ◽  
Significant Concentration

The formation of the mono-oxalato complexes of iron(III) has been examined spectrophotometrically at ionic strength 0.50, between 5 and 25 °C and hydrogen ion concentrations 0.2 to 0.5 M. Evidence is presented that the protonated complex FeHC2O4++ is present in significant concentration in these solutions. The formation quotients of the species FeC2O4++ and FeHC2O4++ for temperatures 5, 15, and 25 °C have been determined and the extinction coefficients at 310 mμ have been estimated.

Complexes of Cu(II) with D-aldonic and D-alduronic acids in aqueous solution

1992 ◽  
Vol 70 (7) ◽  
pp. 2053-2057 ◽  
Author(s):  
Graciela M. Escandar ◽  
Luis F. Sala
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Computer Program ◽  
Quantitative Study ◽  
Hydrogen Ion ◽  
Complex Species ◽  
Ion Concentrations ◽  
Aldonic Acid ◽  
Potentiometric Measurements ◽  
Equilibrium Data

A quantitative study of the equilibria involved in the interaction of Cu(II) ion with D-glucoheptonic, D-gluconic, D-galactonic, D-ribonic, D-glucuronic, and D-galacturonic acids in aqueous medium has been carried out by means of potentiometric measurements of hydrogen ion concentrations at a constant temperature of 20 °C and an ionic strength of 0.10 (NaNO3). The equilibrium data were processed with the FORTRAN computer program BEST. It was found that Cu(II) interacts with D-aldonic acids to form 1:1, 2:2, and 1:2 (M/L) complexes. The copper(II) complexes with D-galacturonic and D-glucuronic acids are considerably weaker than those of D-aldonic acid. Possible structures of the complex species formed are discussed.

A simple and accurate evaluation of hydrogen-ion concentrations in aqueous solutions of fixed ionic strength

1979 ◽  
Vol 105 (2) ◽  
pp. 237-246 ◽  
Author(s):  
M. Molina ◽  
C. Melios ◽  
J.O. Tognolli ◽  
L.C. Luchiari ◽  
M. Jafelicci
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Hydrogen Ion ◽  
Accurate Evaluation ◽  
Ion Concentrations

THE KINETICS OF THE CHELATION OF NICKEL (II) AND 1,10-PHENANTHROLINE

1964 ◽  
Vol 42 (4) ◽  
pp. 934-940 ◽  
Author(s):  
P. F. Barrett ◽  
W. MacF. Smith
Keyword(s):  
Ionic Strength ◽  
Rate Constant ◽  
Order Rate Constant ◽  
Second Order ◽  
Hydrogen Ion ◽  
Kinetic Behavior ◽  
Ion Concentrations ◽  
Order Rate ◽  
Kinetics Of ◽  
Limiting Values

The kinetics of the formation of the bidentate monocomplex of 1,10-phenanthroline and nickel (II) have been examined spectrophotometrically at ionic strength 0.5 over the range of temperatures 8 to 37 °C and over the range of hydrogen ion concentrations 0.01 to 0.30 molar. The kinetic behavior over the range of conditions is consistent with that found at 25 °C by Margerum, Bystroff, and Banks. The limiting values for the second-order rate constant for the reaction at high acidities have been assessed and imply associated values of ΔH≠and ΔS≠ of 9.5 kcal mol−1 and −5.3 e.u. respectively.

scholarly journals Potentiometric measurements of the hydrogen ion concentrations at constant ionic strength.

1989 ◽  
pp. 2028-2034
Author(s):  
Norihisa ISHIKAWA ◽  
Hiroshi MATSUSHITA
Keyword(s):  
Ionic Strength ◽  
Hydrogen Ion ◽  
Constant Ionic Strength ◽  
Ion Concentrations ◽  
Potentiometric Measurements

scholarly journals STUDIES ON PITUITARY LACTOGENIC HORMONE

1940 ◽  
Vol 23 (4) ◽  
pp. 433-438 ◽  
Author(s):  
Choh Hao Li ◽  
William R. Lyons ◽  
Herbert M. Evans
Keyword(s):  
Ionic Strength ◽  
Phosphate Buffer ◽  
Hydrogen Ion ◽  
High Potency ◽  
Ion Concentrations ◽  
Lactogenic Hormone ◽  
Sharp Band ◽  
The Difference ◽  
High Degree

The Tiselius technique of electrophoresis has been used to study the homogeneity and mobility of pituitary lactogenic hormone. The lactogenic preparation employed by us shows only one sharp band in schlieren photographs, indicating a high degree of homogeneity. From the determination of the mobility of the hormone at different hydrogen ion concentrations in acetate and phosphate buffer of ionic strength 0.055, the isoelectric point was found to be 5.70 and the See PDF for Equation value 4.5 x 10–5. The difference in the mobility reported for White's crystalline preparation and that found with our high potency lactogenic preparation is discussed.

scholarly journals The acidity of muscle during maintained contraction

1922 ◽  
Vol 93 (654) ◽  
pp. 406-410
Keyword(s):  
Manganese Dioxide ◽  
Hydrogen Ion ◽  
Ion Concentrations

In 1913, I described a method for recording changes in hydrogen-ion concentrations in tissues, by means of a manganese dioxide electrode in combination with a calomel electrode (1). By this method it was shown that the acidity of muscle probably increased at the same time as, or slightly before, the tension increased, and that the acidity decreased as the muscle relaxed (2). In a paper, which appeared as this note was being prepared for publication, Ritchie states that he has been unable to detect a variation in acidity by the use of manganese dioxide electrodes. I am inclined to think that his failure is due to the injury to the muscles on insertion of wires into its substance. In my own experiments the wires rest on the surface of the muscle.

The measurement of hydrogen ion concentrations with glass electrodes

1924 ◽  
Vol 2 (1) ◽  
pp. 12-17 ◽  
Author(s):  
W E L Brown
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentrations ◽  
Glass Electrodes

The potentiometric determination of hydrogen ion concentrations at higher temperatures

2010 ◽  
Vol 46 (1) ◽  
pp. 18-27 ◽  
Author(s):  
I. M. Kolthoff ◽  
F. Tekelenburg
Keyword(s):  
Hydrogen Ion ◽  
Potentiometric Determination ◽  
Ion Concentrations

scholarly journals In Vivo Studies of Hydrogen Ion Concentrations in the Rumen of the Dairy Cow

1941 ◽  
Vol 24 (8) ◽  
pp. 659-665 ◽  
Author(s):  
Vearl R. Smith
Keyword(s):  
Dairy Cow ◽  
Hydrogen Ion ◽  
In Vivo Studies ◽  
Ion Concentrations
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