Studies on solute solvent interactions in ionic liquid systems

Abstract

Electrolyte solutions historically set themselves apart from ordinary solutions in the study of mixtures. For many years, very few standard text books on solutions (one by Hildebrand and Scott) were written for non- electrolytes. However, it was not until the 1960s and 1970s when liquid state theories had well developed that a common approach to electrolyte and non- electrolyte solutions became possible. This fact be speaks the difficulty in treating electrically charged species located in a dielectric continuum of the solvent. The common basis is the statistical molecular distribution functions (a historical review, given in Falkenhagen Electrolytes ), and a relation (Poisson Boltzmann equation), to correlate the charge distribution in ionatmosphere, to the potential at a central ion which happens to be the focus of the attention, for the Physio-chemical activity. One of the earliest efforts in describing dissolved salts was undertaken by Debye Huckel. This is the Basic model even today; in spite of several attributed lapses in it. A viable model is expected to provide a sensible explanation to several observations made in several angles for the determinations of several Physio- chemical parameters. In this thesis, the author attempted to account for some of the lapses in the theoretical models that became evident by 1990 s and later. This forms the backbone of the work reported in this thesis. The author attempted to obtain experimental data in his dielectric studies on aqueous Sulphates (Cu, Ni, Mn and Co),Chlorides (Cu, Ni, Mn and Co) and Nitrates (Cu, Co, Cd and Cr) of transition metals at 298K with latest Operational amplifier technique, that was designed and fabricated by the author at Godavari Institute of Engineering and Technology, Rajahmundry, A.P. INDIA. This data is applied to calculate thermodynamic parameters like Activity coefficient, Osmotic coefficient and Excess Gibbs energy for these transition metals using well known Pitzer model, Bromley model and Lu and Maurer model.