Determination of Basicities of Organic Solvents and Absolute Electrode Potentials (E0-Values) of Monovalent Ions in Organic Solvents based on Absolute Values of Gibbs Energies of Solvation of Single Ions

Single ion Gibbs energies of monovalent ions in fourteen solvents (water, methanol, NMF, PC, ethanol, n-propanol, iso-propanol, n-butanol, t-butanol, ethylene glycol, acetone, THF, 1,4-dioxan, acetonitrile) with or without (ion–dipole, ion–induced dipole, ion–quadrupole) interactions were determined. The basicity of the solvents was determined from the absolute values of ΔG0solvation(H+) or ΔG0solution(H+) based on single standard state utilising the modified Born equation suggested by Lahiri. The method involves no arbitrary assumptions. A single scale for the absolute electrode potentials (E0 values) has been determined based on calculated Gibbs energies of solvation or solution of single ions. Appropriation of Gibbs energies of solvation of electrolytes into single ion values is not possible. Gibbs energies of formation of electrolytes in solvents must be taken into consideration. Stabilisation energies of electrolytes (MX) in solvents akin to lattice energies in solids were determined.

Calculation of Gibbs Energies of Hydration of Monovalent Ions: Examination of Born Equation and its Reevaluation

The limitations of Born equation and its different modifications for the calculation of Gibbs energies of hydration of ions have been briefly reviewed. A modified method for the calculation of hydration energies of ions has been suggested. The hydration energies thus obtained have been compared with the data in the literature.

Single-ion transfer energetics of some ions using tetraphenylarsonium tetraphenylborate reference electrolyte assumption in aqueous mixtures of urea and glycerol

Single-ion transfer free energies [Formula: see text] and entropies [Formula: see text] of some ions from water to aqueous mixtures of urea and glycerol have been determined using the widely used tetraphenylarsonium tetraphenylborate reference electrolyte assumption from solubility and emf measurements of some appropriate electrolytes at five different temperatures (15 to 35 °C). Analysis of [Formula: see text] and [Formula: see text] values of the ions as well as their respective "chemical" effect, [Formula: see text] and [Formula: see text] as obtained after correcting for their cavity and Born-type electrostatic effects, estimated by the scaled particle theory (SPT) and simple Born equation, respectively, show a complex dependence upon solvent composition. Attempts have been made to explain the observed mirror-image entropie behaviour of simple cations and anions in the light of Kundu etal.'s four-step transfer process and to compare the results with those obtained in other aquo-ionic and nonionic systems. Keywords: single ion, transfer energetics, TATB assumption, aqueous glycerol, aqueous urea.

Ion–ion–solvent interactions in aqueous ionic cosolvent systems. II. Single-ion transfer free energies and entropies using tetraphenylarsonium tetraphenylborate reference electrolyte assumption in aqueous sodium nitrate solvent system

Single-ion tranfer free energies [Formula: see text] and entropies [Formula: see text] of some electrolytes from water to 1, 2, and 4m aqueous NaNO3 solvents have been determined at 25 °C using the widely used tetraphenylarsonium tetraphenylborate (Ph4AsBPh4) reference electrolyte assumption, after due modification for this solvent system. The required [Formula: see text] and [Formula: see text] values of Ph4AsPi, KBPh4, KPi, AgPi, PbPi2, Ag2CrO4, and AgCl where Pi = picrate, were determined by measuring solubilities at 15–35 °C of the solutes except AgCl, the values of which were determined from emf measurements. Analysis of [Formula: see text] and [Formula: see text] values of the ions as well as their respective true interaction effects, [Formula: see text] and [Formula: see text] as obtained after correcting for their cavity effects [Formula: see text] and [Formula: see text] estimated by the scaled particle theory (SPT) and Born-type electrostatic effects, [Formula: see text] and [Formula: see text] computed by simple Born equation, reveals that the behaviour of the ions in this ionic cosolvent system is chiefly guided by one or several effects of ion–ion–solvent, Born and cavity forming interactions. Moreover, a rational explanation has been offered to explain the observed mirror-image entropie behaviour of simple cations and anions in light of Kundu etal.'s four-steps transfer process.