Preferential solvation of hydrogen ions in mixed clusters of water, methanol, and ethanol

1982 ◽  
Vol 104 (20) ◽  
pp. 5314-5318 ◽  
Author(s):  
A. J. Stace ◽  
A. K. Shukla
Keyword(s):  
Preferential Solvation ◽  
Hydrogen Ions ◽  
Mixed Clusters

Ternary complexes of N-carboxymethylaminoacetohydroxamic acid

1981 ◽  
Vol 46 (5) ◽  
pp. 1107-1115 ◽  
Author(s):  
Rolf Karlíček ◽  
Miroslav Polášek ◽  
Vladimír Jokl
Keyword(s):  
Complex Formation ◽  
Ternary System ◽  
Binuclear Complex ◽  
Functional Group ◽  
Hydroxamic Acids ◽  
Ternary Complexes ◽  
Hydrogen Ions ◽  
Ligand Structure ◽  
Excess Copper

The formation of N-carboxymethylaminoacetohydroxamic acid complexes in solutions with excess copper(II) or iron(III) ions or both of them was studied. In the presence of Cu(II), the binuclear complex Cu2H-1L+ was identified; in the ternary system, the complex CuFeH-1L+ was found. This complex formation is necessarily associated with the ligand structure >N-CH2.CO-NHOH and with a new property of hydroxamic acids of this type - detachment of two hydrogen ions from one carbohydroxamic functional group.

Donnan Equilibria in Polymeric Micellar Systems with Weak Polyelectrolyte Shells: The Lowering of the pH Value

1997 ◽  
Vol 62 (11) ◽  
pp. 1730-1736 ◽  
Author(s):  
Petr Munk ◽  
Zdeněk Tuzar ◽  
Karel Procházka
Keyword(s):  
Ionic Strength ◽  
Block Copolymer ◽  
Ph Value ◽  
Electrolyte Solutions ◽  
Hydrogen Ions ◽  
Micellar Systems ◽  
Weak Electrolytes ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Polyelectrolyte Solutions

When two electrolyte solutions are separated and only some of the ions can cross the boundary, the concentrations of these ions are different on both sides of the boundary. This is the well-known Donnan effect. When weak electrolytes are involved, the imbalance includes also hydrogen ions: there is a difference of pH across the boundary and the dissociation of nondiffusible weak electrolytes is suppressed. The effect is very pronounced when the concentration of the weak electrolyte is high and ionic strength is low. The significance of this phenomenon is discussed for polyelectrolyte solutions, and particularly for block copolymer micelles with weak polyelectrolyte shells. The effect is quite dramatic in the latter case.

scholarly journals Constrained Parameter Estimation for a Mechanistic Kinetic Model of Cobalt–Hydrogen Electrochemical Competition during a Cobalt Removal Process

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 387
Author(s):  
Yiting Liang ◽  
Yuanhua Zhang ◽  
Yonggang Li
Keyword(s):  
Parameter Estimation ◽  
Kinetic Model ◽  
Model Parameters ◽  
Hydrogen Ions ◽  
Removal Process ◽  
Cobalt Removal ◽  
Estimation Scheme ◽  
Zinc Hydrometallurgy ◽  
The Impact ◽  
Parameter Estimation Scheme

A mechanistic kinetic model of cobalt–hydrogen electrochemical competition for the cobalt removal process in zinc hydrometallurgical was proposed. In addition, to overcome the parameter estimation difficulties arising from the model nonlinearities and the lack of information on the possible value ranges of parameters to be estimated, a constrained guided parameter estimation scheme was derived based on model equations and experimental data. The proposed model and the parameter estimation scheme have two advantages: (i) The model reflected for the first time the mechanism of the electrochemical competition between cobalt and hydrogen ions in the process of cobalt removal in zinc hydrometallurgy; (ii) The proposed constrained parameter estimation scheme did not depend on the information of the possible value ranges of parameters to be estimated; (iii) the constraint conditions provided in that scheme directly linked the experimental phenomenon metrics to the model parameters thereby providing deeper insights into the model parameters for model users. Numerical experiments showed that the proposed constrained parameter estimation algorithm significantly improved the estimation efficiency. Meanwhile, the proposed cobalt–hydrogen electrochemical competition model allowed for accurate simulation of the impact of hydrogen ions on cobalt removal rate as well as simulation of the trend of hydrogen ion concentration, which would be helpful for the actual cobalt removal process in zinc hydrometallurgy.

Results of Pilot Comparisons of National Standards for the Activity of Hydrogen Ions in Aqueous Solutions

2021 ◽  
Author(s):  
S. V. Prokunin ◽  
A. N. Shchipunov ◽  
D. A. Vengina ◽  
F. Bastkowskiy ◽  
E. Uysal ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
National Standards ◽  
Hydrogen Ions
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