International Conference on Multidisciplinary Research & Practice Page | 358 Volume I Issue VIII IJRSI ISSN 2321-2705 Ultrasonic Study and Allied Physical Parameters of Uni-Univalent Mixed Electrolytes in Formamide Dr. Nidhi Sharma 1 , Ms. Swagat Ebhad 2 1 Department of Engineering Chemistry, PGMCOE, Wagholi, Pune 2 Department of Engineering Physics, PGMCOE, Wagholi, Pune Abstract — Ultrasonic velocities (u) and densities(ρ) of mixed electrolytes : NaBr + NaCl, KBr + KCl, NaBr + NaNO3, KBr + KNO3, CH3COONa + NaNO3 and CH3COOK + KNO3 in Formamide (non – aqueous solvent) have been measured at a constant frequency of 10 M Hz at 298.15 K.. Acoustical parameters, such as, apparent molar compressibility (Фk), inter molecular free length (Lf), specific acoustic impedance (Z), solvation number (Sn) and relative association constant (RA) have been obtained are computed to assess the ion-solvent and ion – ion interaction in these solutions. It is found that the interactions depend on concentration, ionic size and nature of metal ion. Ions behave as structure breaker for the associated clusters of solvent molecules, especially in dilute solution, as evidenced from the trend in the solvation number with molarity. It is also found that the strength of ion-dipole interaction in non aqueous solution of the metal ion is also dependent on concentration of the solution. Keywords -- ultrasonic velocities, inter-molecular free length, adiabatic compressibility, apparent molar compressibility, specific acoustic impedance and solvation number. I. INTRODUCTION ixed electrolytes are very important as they are found in numerous processes in chemical industry. They occur in enormous quantities in the water of ocean and play an important role in the physiological process of body fluids and cell equilibria. From the survey of literature, it appears that no ultrasonic studies on the mixed electrolyte systems vis-à-vis ion-solvent and ion-ion interactions in purely non-aqueous media have been reported so far. It has been known that the di-electric constant of the medium plays a very important role concerning the behaviour of electrolytes in the solutions1. The solvent formamide is unusual in its properties, in that it is strongly self-associated through extensive network of hydrogen- bonds2,3 and it’s di-electric constant and dipole moment (฀ =109.5 and D= 3.68 at 298.15K)1 are very high. With this aim in view comprehensive studies on the determination of densities and ultrasonic velocities of some uni-univalent mixed electrolytes viz: : NaBr + NaCl, KBr + KCl, NaBr + NaNO3, KBr + KNO3, CH3COONa + NaNO3 and CH3COOK + KNO3, in Formamide, an aprotic solvent, have been undertaken. The main thrust of this study is to examine the acoustic behaviour and other parameters of the above uni-univalent mixed electrolytes systems. Application of acoustic methods have showed extensive possibility in the fields of solution chemistry, physical chemistry, biochemistry, chemical engineering and process control for a fundamental understanding of many phenomena in solutions and liquid systems 11,12. It is also possible to estimate the solvation numbers of the electrolyte solutions from the molar compressibility value at infinite dilution. Metal ions play an important role in chemical and biological systems so the solvation of ions in these systems is a key issue to understand the chemical and dynamical processes 13,14. Propagation of the sound wave perturbs the equilibrium between solute and solvent molecules and relaxation process are setup leading to excess absorption of the sound wave. Endo et al. 15 studied the ultrasonic velocity of electrolytes of high solubility and showed a decrease in the absorption with increase in concentration. Ultrasonic velocity parameters were used to study interactions in Binary 16- 17 and ternary 18 systems, as well as the ion-solvent and inter ionic interaction in aqueous 19 , mixed aqueous 20 and non aqueous 21 systems. Bhat and Shiva Kumar 14 studied on acoustic behaviour of potassium thiocyanate in aqueous and various non-aqueous solvents and determined the values of apparent molar compressibility (Φk), apparent molar volume (Φv) and limiting apparent molar compressibility (Φ0k), limiting apparent molar volume (Φ0v) . The ion – ion and ion- solvent interactions have been discussed in terms of these parameters. The review of literature on acoustical studies of solutions reveal that the ultrasonic velocity data as such do not provide significant information about the native and relative strength of various types of inter molecular and inter- ionic interactions between components. Hence in present study, their derived parameters of non aqueous solutions of mixed electrolytes such as adiabatic compressibility (βad), apparent molar compressibility (Фk), inter molecular free length (Lf), specific acoustic impedance (Z), solvation number (Sn) and relative association constant (RA) have been calculated to give more emphasis on such interactions. M