Freezing points, osmotic coefficients, and activity coefficients of salts in N-methylacetamide. I. Alkali halides and nitrates

1971 ◽  
Vol 75 (15) ◽  
pp. 2313-2318 ◽  
Author(s):  
R. H. Wood ◽  
R. K. Wicker ◽  
R. W. Kreis
Keyword(s):  
Activity Coefficients ◽  
Osmotic Coefficients ◽  
Alkali Halides ◽  
Freezing Points

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

Thermodynamics of electrolyte solutions: activity coefficients of NaCl in the NaCl–NiCl2–H2O system at 25, 35, and 45 °C

1990 ◽  
Vol 68 (2) ◽  
pp. 294-297 ◽  
Author(s):  
Ch. Venkateswarlu ◽  
J. Ananthaswamy
Keyword(s):  
Activity Coefficients ◽  
Silver Chloride ◽  
Osmotic Coefficients ◽  
Reference Electrode ◽  
Nickel Chloride ◽  
Electrolyte Solutions ◽  
Pitzer Formalism ◽  
Harned Coefficients ◽  
Silver Silver ◽  
Silver Silver Chloride

The activity coefficients of NaCl in the NaCl–NiCl2–H2O system were estimated at 25, 35, and 45 °C and total ionic strengths of 0.5, 1.0, 2.0, and 3.0 m by an EMF method using a Na-ion selective electrode and a silver–silver chloride reference electrode. The Harned coefficients were calculated at all the temperatures studied. At 25 °C the data were analysed using the Pitzer formalism. The osmotic coefficients and the excess free energies of mixing were also calculated at 25 °C. Keywords: activity coefficients, sodium chloride, nickel chloride, Pitzer equations, thermodynamics.

Further studies of 2:2 electrolytes: osmotic and activity coefficients

1976 ◽  
Vol 351 (1667) ◽  
pp. 471-479 ◽  
Keyword(s):  
Activity Coefficients ◽  
Hydration Number ◽  
Osmotic Coefficients ◽  
Linear Term ◽  
Hydration Effect ◽  
Electrostatic Contribution ◽  
Better Than

A satisfactory interpretation of the osmotic coefficients of all 2:2 electro­lytes has been attained from 0.1 up to 3 and 4 mol/kg concentrations. The treatment uses an electrostatic contribution according to the Kirkwood Glueckauf-Bjerrum formula (Glueckauf 1969) plus a ‘Müller’ extension term, and an effectively linear term in m , arising mainly from a hydration effect with a steadily diminishing hydration number. Two constants only determine the behaviour of the osmotic coefficients: the distances of closest approach of the ions ( a ) and the constant ( K ) of the linear term. The constants obtained from pure CaSO 4 and MgSO 4 solutions were then employed to calculate the activity coefficients of CaSO 4 in concentrated MgS0 4 solutions (from 0.026 up to 2.6 mol/kg), the observed and calculated γ -data agreeing to better than 1%.

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