Studies in ion solvation in non-aqueous solvents and their aqueous mixtures. Part 16.—Free energies of transfer of sodium bromide and iodide from water to 10–99%(w/w) methanol + water mixtures at 25°C

1973 ◽  
Vol 69 (0) ◽  
pp. 1711 ◽  
Author(s):  
David Feakins ◽  
Philip J. Voice
Keyword(s):  
Sodium Bromide ◽  
Ion Solvation ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Free Energies Of Transfer

Determination of absolute transfer free energies of hydroxyl ion from water to aqueous 2-methoxy ethanol

1981 ◽  
Vol 59 (7) ◽  
pp. 1153-1159 ◽  
Author(s):  
Abhijit Bhattacharya ◽  
Asim K. Das ◽  
Kiron K. Kundu
Keyword(s):  
Ethylene Glycol ◽  
Mixed Solvents ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Free Energies Of Transfer ◽  
Hydroxyl Ion ◽  
Relative Stabilization ◽  
Solvent Systems ◽  
Reference Electrolyte

Absolute standard free energies of transfer ΔGt0 of OH− from water to aqueous mixtures of 2-methoxy ethanol (ME) have been evaluated at 298.15 K by combining the apparent transfer free energies of the lyate ion that were obtained from the standard emf's of the double cell:[Formula: see text]and that from the autoionization constants of these mixed solvents determined by use of the cell comprising H2– and Ag–AgCl electrodes. The required ΔGt0 values of K+ and H+ were determined earlier using the well-known tetraphenyl arsonium tetraphenyl boride (TATB) reference electrolyte method. These values and their non-Born type contributions in particular, are found to be increasingly positive in water-rich compositions, indicating that the relative stabilization of OH− and the acidity of the mixed solvents decrease with increasing cosolvent composition. These, when compared with those in aqueous mixtures of ethylene glycol and 1,2-dimethoxy ethane, are found to lie intermediate between the latter solvent systems conforming to what is expected from the structural and electronic features of the cosolvents.

Free energies of transfer of some single ions from ethylene glycol to its isodielectric mixtures with acetonitrile at 25 °C

1979 ◽  
Vol 57 (18) ◽  
pp. 2476-2481 ◽  
Author(s):  
Kumardev Bose ◽  
Kiron K. Kundu
Keyword(s):  
Ethylene Glycol ◽  
Aprotic Solvent ◽  
Ion Solvation ◽  
Free Energies ◽  
Solvent Interactions ◽  
Free Energies Of Transfer ◽  
Isodielectric Mixtures ◽  
The Individual ◽  
Reference Electrolyte ◽  
Electrolyte Ph

Free energies of transfer (ΔGt0) of the reference electrolyte Ph4AsBPh4 (Ph = phenyl) from ethylene glycol to its approximately isodielectric mixtures with acetonitrile have been determined at 25 °C from the measurement of the solubilities of KPi, Ph4AsPi, and KBPh (Pi = picrate) in these solvents. Using the assumption [Formula: see text] values for the individual ions K+, Pi−, Ph4As+, and Ph4 s− have been estimated. These, in conjunction with previously determined values of ΔGt0 for MCl (M = Li, Na, K, Rb, Cs, and H), KBr and KI have provided ΔGt0 values for Cl−, Br−, I−, and M+ ions. Ionic ΔGt0's have been interpreted in terms of specific ion–solvent interactions. The contrasting behaviour of ethylene glycol and acetonitrile in ion-solvation is shown to be characteristic of the protic and dipolar aprotic solvent types respectively.

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