Osmotic coefficients and activity coefficients in binary water/5-(hydroxymethyl)furfural and in ternary water/5-(hydroxymethyl)furfural/salt solutions at 298.15 K

2019 ◽  
Vol 139 ◽  
pp. 105878
Author(s):  
G. Grundl ◽  
E.N. Tsurko ◽  
R. Neueder ◽  
W. Kunz
1964 ◽  
Vol 206 (5) ◽  
pp. 1111-1117 ◽  
Author(s):  
Edward W. Moore ◽  
John M. Dietschy

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.


1965 ◽  
Vol 20 (6) ◽  
pp. 1332-1336 ◽  
Author(s):  
Edward W. Moore ◽  
James W. Ross

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


1990 ◽  
Vol 68 (2) ◽  
pp. 294-297 ◽  
Author(s):  
Ch. Venkateswarlu ◽  
J. Ananthaswamy

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.


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