Liquid-junction potentials in ethylenediamine: Attempted calculations and evaluations using concentration cells

1977 ◽  
Vol 55 (16) ◽  
pp. 2962-2965 ◽  
Author(s):  
Suraj P. Makhija

Concentration cells of the type M(Hg)|MX(1)||MX(2)|M(Hg), where M(Hg) is potassium amalgam or sodium amalgam, were investigated with three electrolytes, potassium bromide, potassium iodide, and sodium iodide. An attempt was made to determine the necessity and magnitude of liquid-junction potential corrections. Only in the case of sodium iodide are the ionic mobilities of cation and anion quite different in ethylenediamine, and liquid-junction potential corrections are necessary to obtain agreement between observed and calculated data. The limiting equations of Nernst and of Lewis and Sargent were found to be appropriate for calculating liquid-junction potentials in ethylenediamine, provided that calculated activities were used in these equations.

1983 ◽  
Vol 36 (10) ◽  
pp. 1997 ◽  
Author(s):  
K Schwabe ◽  
W Hoffmann ◽  
C Queck

The comparison of S2ΔS1G°tr(E1) with the sum of the values for the corresponding cation and anion S2ΔS1G°tr(Ct+)~S2ΔS1G°tr(X-) (measured) with Owen cells, gained by double extrapolation and by the assumption that the liquid junction potential at 1→0 may be neglected) gives values which differ by not more than ±5%. Most of the investigated acids allow the conclusion that the pH values, measured in cells with transference, and having the same electrodes, give good information on the acidity of the organic solvent and its water mixtures, referred to the standard state in water. That means that the pH, changed to the same H+ concentration in the solvent compared with that in water, is essentially an effect of the free energy of transfer of the hydrogen ion and not of very high liquid junction potentials.


1974 ◽  
Vol 27 (8) ◽  
pp. 1617 ◽  
Author(s):  
JW Diggle ◽  
AJ Parker

The liquid junction potential at a number of dissimilar solvent junctions has been determined within the framework of the tetraphenylarsonium tetraphenylborate extrathermodynamic assumption. The junctions investigated were H2O/solvent S, MeCN/solvent S and propylene carbonate (pcar)/solvent S. The liquid junction potentials obtained have primarily been related to solvent-solvent interactions at the junction, being, for water, lowest for an alcohol /H2O junction (10 mV) and the greatest for a dipolar aprotic/H20 junction (100-200 mV).


Electrochem ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 197-215
Author(s):  
Jerzy J. Jasielec

This work is aimed to give an electrochemical insight into the ionic transport phenomena in the cellular environment of organized brain tissue. The Nernst–Planck–Poisson (NPP) model is presented, and its applications in the description of electrodiffusion phenomena relevant in nanoscale neurophysiology are reviewed. These phenomena include: the signal propagation in neurons, the liquid junction potential in extracellular space, electrochemical transport in ion channels, the electrical potential distortions invisible to patch-clamp technique, and calcium transport through mitochondrial membrane. The limitations, as well as the extensions of the NPP model that allow us to overcome these limitations, are also discussed.


1992 ◽  
Vol 45 (10) ◽  
pp. 1633 ◽  
Author(s):  
A Berne ◽  
C Kahanda ◽  
O Popovych

The component of the liquid-junction potential due to the diffusion of ions across an interface of electrolyte solutions in different solvents was formulated by taking into account the solvent dependence of the transport numbers, t, and of the chemical potentials of ions in the interphase region as determined from experimental data on their variation in the mixed-solvent compositions. The new equation was applied to NaCl/NaCl and HCl/HCl junctions between water and methanol-water solvents over the entire solvent range. Significant differences between the results obtained with the new equation and the old formulation, which treated the transport numbers as solvent-independent, were observed only for the HCl junctions involving 90-100 wt % aqueous methanol, where tH exhibits a sharp minimum as a function of the solvent composition.


1985 ◽  
Vol 31 (3) ◽  
pp. 482-485 ◽  
Author(s):  
A H Maas ◽  
O Siggaard-Andersen ◽  
H F Weisberg ◽  
W G Zijlstra

Abstract For clinical purposes the activities of Na+ and K+ obtained with ion-selective electrodes in undiluted whole blood or serum should be multiplied by an appropriate factor to obtain the same values as the substance concentrations obtained by flame photometry. The factor is primarily dependent on the mass concentration of water in normal plasma divided by the molal activity coefficient of Na+ (or K+) of normal plasma. We discuss the value of the molal activity coefficient of Na+ obtained by theoretical calculations and by direct measurement. The discrepancies between theory and measurement (gamma Na+ of 0.747 and 0.73, respectively) may be due to some binding of Na+ (protein binding or ion pair formation), a small and variable residual liquid-junction potential, or certainty about the appropriate value for the ionic strength of normal plasma (0.16 mol/kg or somewhat higher).


1990 ◽  
Vol 283 (1-2) ◽  
pp. 435-440 ◽  
Author(s):  
Kosuke Izutsu ◽  
Toshio Nakamura ◽  
Mitsuo Muramatsu

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