Physico-Chemical Studies Of Different Solutions Of Electrolytes NH4C1, FeC13 and NiC12) IN Mixed Solvents (Water-DMSO)

Abstract

The volumetric, viscometric and some other related properties of DMSO in aqueous solutions and some electrolytes such as NH4C1, NiC12 and FeCl3 in water, DMSO and mixed solvents have been measured. The apparent molal volumes, and viscosities, of NH4Cl,NiC12 and FeCl3 in water and water-DMSO solutions were studied as a function of concentration at a wide range of temperatures of 288, 293, 298, 303, 308 and 313 K. The apparent molal volumes at infinite dilutions (limiting apparent molal volume) of these values to the zero concentrations which is practically equal to the partial molal volume. Limiting apparent molal volume for all the three electrolytes were determined by extrapolating co electrolytes studied showed higher values in aqueous DMSO solution then those in aqueous solution in the temperature range of 288 K to 313 K. Apparent molal volumes, , is depended upon the electrolyte concentration as well as on the temperature. Apparent molal volumes showed the gradual decrease of volume with concentration except FeCl3 in water and in pure DMSO solution. The value of viscosities increase in molality of the electrolytes except NH4Cl. No significant change of viscosity observed for NH4Cl with increase in molality in aqueous and in 20% aqueous-DMSO solutions. The viscosities, il for all the studied electrolytes are greater in aqueous DMSO solvent system than those in water system alone indicating that electrolytes in aqueous DMSO systems are more structural than those in aqueous system.Viscosity coefficients (A and B) for the above systems were also determined for the Jones Dole equation. B values for NiC12 and FeCl3 were found to be positive that indicate these electrolytes exhibit structure making behavior in water and in water-DMSO solutions. The B value is negative in water and water-DMSO for NH4C1.This indicates that NH4Cl salt behaves as a water structure breaker in aqueous and aqueous DMSO system. The coefficient A represents the solute-solute interactions coupled with size and shape effect of the solute and to some extent solute-solvent interactions. A coefficient was obtained with an irregular variation. The behaviors of three solutes in binary and ternary systems were discussed in terms of the charge, size and hydrogen bonding effect.