scholarly journals Single ion activity coefficients of chloride ions in aqueous sodium chloride and magnesium chloride estimated potentiometrically based on ionic liquid salt bridge at 298 K

2021 ◽  
Vol 124 ◽  
pp. 106953
Author(s):  
Takashi Kakiuchi ◽  
Masaki Hisazumi ◽  
Yasufumi Moriyama ◽  
Masahiro Yamamoto
Keyword(s):  
Ionic Liquid ◽  
Sodium Chloride ◽  
Activity Coefficients ◽  
Magnesium Chloride ◽  
Salt Bridge ◽  
Chloride Ions ◽  
Aqueous Sodium ◽  
Liquid Salt ◽  
Ion Activity ◽  
Single Ion Activity

scholarly journals New Data on Activity Coefficients of Potassium, Nitrate, and Chloride Ions in Aqueous Solutions of KNO3 and KCl by Ion Selective Electrodes

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Debasmita Dash ◽  
Shekhar Kumar ◽  
C. Mallika ◽  
U. Kamachi Mudali
Keyword(s):  
Activity Coefficient ◽  
Aqueous Solutions ◽  
Activity Coefficients ◽  
Reference Electrode ◽  
Potassium Nitrate ◽  
Chloride Ions ◽  
Ion Selective Electrodes ◽  
Ion Activity ◽  
Double Junction ◽  
Single Ion Activity

Ion selective electrodes (ISEs) are used to measure the single-ion activity coefficients in aqueous solutions of KNO3 and KCl at 298.15 K against a double-junction reference electrode. The EMF responses of ISEs up to 0.01 m are plotted to obtain the slope and intercept values. The obtained slopes and intercepts are used in Nernst equation for higher concentrated solutions for calculation of individual ion activity coefficient. The mean ionic activity coefficients are estimated from single ion activity coefficient, and the obtained results are compared with the literature values.

scholarly journals Current Stage and Perspectives of pH Measurements by Use of Ionic Liquid Salt Bridge

2016 ◽  
Vol 65 (4) ◽  
pp. 181-191 ◽  
Author(s):  
Takashi KAKIUCHI ◽  
Masahiro YAMAMOTO
Keyword(s):  
Ionic Liquid ◽  
Salt Bridge ◽  
Ph Measurements ◽  
Liquid Salt ◽  
Current Stage

scholarly journals Towards the Understanding of Water-in-Salt Electrolytes: Individual Ion Activities and Liquid Junction Potentials in Highly Concentrated Aqueous Solutions

2021 ◽  
Author(s):  
Damien Degoulange ◽  
Nicolas Dubouis ◽  
Alexis Grimaud
Keyword(s):  
Activity Coefficients ◽  
Operating Voltage ◽  
Redox Potentials ◽  
Liquid Junction ◽  
Nernst Potential ◽  
Concentrated Electrolytes ◽  
Ion Activity ◽  
Ion Activities ◽  
Single Ion Activity ◽  
Increased Activity

Highly concentrated electrolytes were recently proposed to improve the performances of aqueous electrochemical systems by delaying the water splitting and increasing the operating voltage for battery applications. While advances were made regarding their implementation in practical devices, debate exists regarding the physical origin for the delayed water reduction occurring at the electrode/electrolyte interface. Evidently, one difficulty resides in our lack of knowledge regarding ions activity arising from this novel class of electrolyte, it being necessary to estimate the Nernst potential of associated redox reactions such as Li<sup>+</sup> intercalation or the hydrogen evolution reaction. In this work, we first measured the potential shift of electrodes selective to either Li<sup>+</sup>, H<sup>+</sup> or Zn<sup>2+</sup> ions from diluted to highly concentrated regimes in LiCl or LiTFSI solutions. Observing similar shifts for these different cations and environments, we establish that shifts in redox potentials from diluted to highly concentrated regime originates in large from an increase junction potential, it being dependent on the ions activity coefficients that increase with concentration. While our study shows that single ion activity coefficients, unlike mean ion activity coefficients, cannot be captured by any electrochemical means, we demonstrate that protons concentration increases by approximatively two orders of magnitude from 1 mol.kg<sup>-1</sup> to 15-20 mol.kg<sup>-1</sup> solutions. Combined with the increased activity coefficients, this increases the activity of protons and thus the pH of highly concentrated solutions which appears acidic.

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