Ion association and solvation characteristics of Li+, Na+ and K+ ions in binary mixtures of 2-Aminoethanol + N,N-Dimethylacetamide probed by conductometry study at 298.15 K and 308.15 K
- Vol.61(3), Mar
- New Delhi CSIR 2022
- 245-253p.
Molar conductances (Λ) of LiClO4, NaClO4, KSCN, Bu4NSCN, Bu4NClO4 and Bu4NBPh4 in binary solvent mixtures of 2-aminoethanol (AE) and N,N-dimethylacetamide (DMA) containing 25, 50, 60, 80 and 100 mol% DMA have been measured at 298.15 K and 308.15 K in the concentration range of (30-500) × 10-3 mol kg-1. The conductance data of the electrolytes in the binary mixtures of AE+DMA are analyzed using Shedlovsky’s equation to evaluate limiting molar conductances (Λo), association constants (KA), Walden products (Λoηo), hydrodynamic radii (RH) and the standard free energies of association (∆GA0). The individual limiting ionic molar conductances are obtained using the reference electrolyte tetrabutylammonium perchlorate (Bu4NClO4) and tetrabutylammonium tetraphenylborate (Bu4NBPh4). A modified form of Stokes’ law helped to determine the solvated ionic radii (ri) in solutions and are assessed in the facet of ion-ion, ion-solvent interactions and show structural changes in the binary mixtures. The results has revealed that the solvated radii (ri) values of Li+, Na+ and K+ ions show preferential solvation of these ions by DMA in AE+DMA binary mixtures and these interactions get weaker with the increase in temperature. Also, the preferential solvation and ion-solvent interactions of these ions in binary mixtures are proved by the analysis of Walden products (Λoηo) and the standard free energies of association (∆GA0) with the effect of temperature.