The Microscopic Free Energies of Solvation for K<SUP>+</SUP>, Rb<SUP>+</SUP> and Cs<SUP>+</SUP> in Mixed Methanol (MeOH)-Dimethylformamide (DMFA) Solvents at 298.15 K

Abstract

The microscopic charging ( ∆ G t charging), ion-dipole ( ∆ G t ion-dipole) and ion-induced dipole ( ∆ G t ioninduced dipole) free energies of transfer for some ions from methanol to mixed methanol (MeOH)-dimethylformamide (DMFA) solvents were calculated. These ions are potassium, rubidium and cesium. These theoretical free energies were compared with that of experimental values and the difference excess free energies of solvation were discussed. I t was observed that the excess free energies for all ions are positive and follow the following order:. Indicating more solvation behaviour by increasing the percentage of DMFA in the mixed solvents due to more attraction of these ions in the range rich in DMFA Keywords Microscopic free energy, potassium,robedium, cesium,excess free energy, organic solvents Calculations and ResultsThe electrostatic free energies of transfer ∆ G t (el) is known as the microscopic free energies of interaction [1]. The solvation free energies of ions is important in the applications of all fields,chemistry,physics and theoretical sciencesto obtain the corresponding energies of salts.Also chemical reactions can be theoreticaly expected to happen by knowing the free energy values for reactants and products. When we know the free energies of the ions we can easily obtain that for any simple, heavy element, lanthanide and actinide salts,which facilitate the explanation of different reactions.The salvation free energy of an ion has been formulated by number of authors cited by Covington[1] as a composite of neutral and electrostatic contribution.A neutral part may be considered to be equivalent to the salvation energy of uncharged molecules analogous to the ion in structure and size. The electrostatic contribution of the free energy is not exact evaluated before.In this work we did simple view to evaluate the electrostatic free energies and compare it with the available experimental values done by using the asymmetric Ph 4 AsPh 4 B (tetraphenylarsonium tetraphenylborate) assumption for evaluating single ion thermodynamics [Popovych...][2].

Thermodynamic Parameters for Solvation of Nano ZNO and Its Dopes In 50% DMSO - 50% DMF (V/V) Solutions at Different Temperatures

“…The solubility of nano zinc oxide and nano zinc oxide doped were measured by tacking 1 ml of each saturated solution putting in a small weighed beaker (10 ml) and evaporated under I.R. lamp till dryness [20,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] and then weighed with average error in weight about 0.0001 g [20,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44].…”