Isopiestic determination of osmotic coefficients and evaluation of activity coefficients of aqueous mixtures of sodium and potassium chloride at 45°C

1997 ◽  
Vol 131 (1-2) ◽  
pp. 189-196 ◽  
Author(s):  
Miguel A. Flesia ◽  
María R. Gennero de Chialvo ◽  
Abel C. Chialvo
Keyword(s):  
Potassium Chloride ◽  
Activity Coefficients ◽  
Osmotic Coefficients ◽  
Aqueous Mixtures ◽  
Sodium And Potassium

NaCl and CaCl2 activity coefficients in mixed aqueous solutions

1965 ◽  
Vol 20 (6) ◽  
pp. 1332-1336 ◽  
Author(s):  
Edward W. Moore ◽  
James W. Ross
Keyword(s):  
Ionic Strength ◽  
Activity Coefficients ◽  
Technical Assistance ◽  
Osmotic Coefficients ◽  
Electrode System ◽  
Glass Electrode ◽  
Concentration Data ◽  
Harned's Rule ◽  
Potentiometric Measurement

In the investigation of numerous physiological phenomena it is the activity of an ion species which is desired, rather than stoichiometric concentration. The calculation of mean ionic activity from known concentration data requires accurate activity coefficients (ggr). This report concerns the determination of ggrNaCl and ggrCaCl2 in mixed NaCl-CaCl2 solutions by potentiometric measurement with a sodium-selective glass electrode-Ag/AgCl electrode system over the ionic strength range 0.05–0.5 m. Log ggrNaCl varied linearly, at constant total ionic strength, with the ionic strength of CaCl2 in the mixture, in accordance with Harned's rule. From data thus obtained, ggrCaCl2 coefficients in such mixed solutions have been calculated and compared with values calculated from published osmotic data. Resulting activity coefficient curves for ggrCaCl2 are presented over the concentration range encountered in serum and other extracellular fluids. Note: (With the Technical Assistance of Leonard Kaye and Leonard L. Anderson) glass electrodes; ion interaction; electrolyte metabolism; Harned's rule; membrane transport; osmotic coefficients Submitted on March 11, 1965

scholarly journals Isopiestic Determination of the Osmotic and Activity Coefficients of Aqueous Mixtures of Li2SO4 and MgSO4

1993 ◽  
Vol 9 (03) ◽  
pp. 366-373 ◽  
Author(s):  
Zhang Zhong ◽  
◽  
Yao Yan ◽  
Song Peng-Sheng ◽  
Chen Jing-Qing
Keyword(s):  
Activity Coefficients ◽  
Aqueous Mixtures

Na and K activity coefficients in bile and bile salts determined by glass electrodes

1964 ◽  
Vol 206 (5) ◽  
pp. 1111-1117 ◽  
Author(s):  
Edward W. Moore ◽  
John M. Dietschy
Keyword(s):  
Bile Salt ◽  
Activity Coefficients ◽  
Freezing Point ◽  
Osmotic Coefficients ◽  
Ionic Species ◽  
Salt Solutions ◽  
Glass Electrodes ◽  
Sodium And Potassium

Mathematical formulations for transmembrane potential differences are expressed in terms of ionic activities rather than ionic concentrations, and require knowledge of the activity coefficients of a given ionic species in mixed solutions. Cation-selective glass electrodes have been used to determine sodium and potassium activity coefficients in pure bile salt solutions and in native bile, relative to standard NaCl or KCl solutions. Comparison was made with osmotic coefficients determined by freezing-point depression. Both sodium and potassium activity coefficients in bile salt solutions and in bile were lower than those for NaCl or KCl solutions at corresponding concentrations, with potassium coefficients being lower than those for sodium. These derived activity coefficients have been used experimentally in in vivo and in vitro gall bladder preparations with close agreement between observed potentials and those predicted by the Hodgkin-Katz equation.

The activity coefficients of elctrolytes with particular reference to aqueous mixtures of 2:2 With 1:1 electrolytes

1971 ◽  
Vol 321 (1547) ◽  
pp. 515-543 ◽  
Keyword(s):  
Exact Solution ◽  
Activity Coefficients ◽  
Infinite Dilution ◽  
Osmotic Coefficients ◽  
Ion Association ◽  
Aqueous Mixtures ◽  
General Application ◽  
Poisson Boltzmann ◽  
High Concentrations ◽  
Charged Ions

Müller’s method for the exact solution of the Poisson-Boltzm an equation (P.B.M.) has been used to produce tables for general application, for the potential, for the activity coefficients and for the osmotic coefficients of 2:2 electrolytes in aqueous solutions, both alone and in the presence of strong 1:1 electrolyte. The activity coefficients for 2:2 electrolytes were found to be equivalent to those derived by Bjerrum ’s method of ionic association up to values of s/a = z 2 e 2 / ϵkTa of about 9. Beyond this value the Poisson-Boltzmann-Müller values of the activity coefficients are significantly higher (about 10% at s/a = 11) and it is shown that the Bjerrum method is better in this range. The P.B.M. calculations show that in the presence of 1:1 electrolyte the Bjerrum treatment of ion association does not give a constant dissociation constant for a 2:2 electrolyte—even at infinite dilution of the latter—and this makes the Bjerrum method less useful when dealing with mixtures of 2:2 and 1:1 electrolytes. The P.B.M. method has been applied to the activity coefficients at CaSO 4 in NaCl solutions (up to 6 mol/1 strength) in the temperature range from 0 to 95 °C ( s/a from 7.85 to 9.05). The results shows very clearly the advantage of using the Kirkwood-Glueckauf approximation rather than the Debye-Hückel term (both in combination with the Müller extension term) when dealing with highly charged ions in solutions of high concentrations.

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