Liquid Junction Potential between Electrolyte Solutions in Different Solvents Studied by Use of Mixed Solvent/Pure Solvent Junctions

2008 ◽  
Vol 81 (6) ◽  
pp. 703-710 ◽  
Author(s):  
Kosuke Izutsu
Keyword(s):  
Mixed Solvent ◽  
Electrolyte Solutions ◽  
Liquid Junction Potential ◽  
Liquid Junction ◽  
Pure Solvent ◽  
Junction Potential

An Improved Equation for the Liquid Junction Potential at the Interface of Different Solvents

1992 ◽  
Vol 45 (10) ◽  
pp. 1633 ◽  
Author(s):  
A Berne ◽  
C Kahanda ◽  
O Popovych
Keyword(s):  
Mixed Solvent ◽  
Electrolyte Solutions ◽  
Transport Numbers ◽  
Liquid Junction Potential ◽  
Aqueous Methanol ◽  
Liquid Junction ◽  
Chemical Potentials ◽  
Solvent Dependence ◽  
New Equation ◽  
Junction Potential

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.

Evaluation of Ionic and Solvent Components of the Liquid-Junction Potential Between Aqueous and Several Aquo-Organic Solutions

1994 ◽  
Vol 47 (5) ◽  
pp. 921 ◽  
Author(s):  
C Kahanda ◽  
O Popovych
Keyword(s):  
Mixed Solvent ◽  
Approximate Equation ◽  
Transport Numbers ◽  
Liquid Junction Potential ◽  
Liquid Junction ◽  
Solvated Ions ◽  
A Cell ◽  
Solvent Component ◽  
Organic Solutions ◽  
Junction Potential

Values of Ej,ion, the ionic component of the liquid-junction potential Ej, were calculated for the HCl,H2O |HCl,S2 and KCl,H2O | KCl,S2 junctions, where S2 was EtOH-H2O, HCONMe2- H2O and Me2SO-H2O solvents, and for the AgNO3,H2O | AgNO3,MeCN-H2O junction, over the entire mixed-solvent ranges. Both the old approximate equation for Ej,ion and our improved equation, which accounts for the variation of the ionic transport numbers t and chemical potentials Go in the interphase region, were used. Significant differences between the two equations were observed for systems where the t and ΔtG° functions dnisplayed extrema against the mixed-solvent composition. The highest Ej,ion value was 395 mV, for the HCl,H2O | HCl,Me2SO junction. Values of Ej,s,the solvent component of Ej, were calculated by subtracting the corresponding Ej,ion values from the total Ej, which was evaluated in each case from the e.m.f , of a cell with the liquid junction of interest and the transfer activity coefficient of the electroactive ion, estimated by the tetraphenylborate assumption. The magnitude of Ej,s was significant for the junctions between H2O and most of the solvents, and was particularly large for those involving dipolar aprotic solvents and highly solvated ions. The maximum Ej,s value was -201 mV, observed for the junction HCl,H2O|HCl,100% Me2SO.

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