Riju Chanda

Apparent molar volume, viscosity, and adiabatic compressibility of some mineral sulfates in aqueous binary mixtures of formamide at 298.15, 308.15, and 318.15 K

The densities and viscosities of several sulfates, viz., ammonium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, zinc sulfate and cadmium sulfate in aqueous binary mixtures of formamide (FA) have been determined at 298.15, 308.15, and 318.15 K and at atmospheric pressure. The ultrasonic speeds of the electrolytic solutions have also been measured at 298.15 K. Apparent molar volumes (ϕV), viscosity B-coefficients and adiabatic compressibilities (KS) of these electrolytic solutions were calculated from the experimental densitiy, viscosity and acoustic data. The density and viscosity data were evaluated by using Masson’s and Jones-Dole equation respectively; the derived parameters have been analyzed in terms of ion-ion and ion-solvent interactions. The structure making/breaking capacities of the electrolytes have been inferred from the sign of (∂2ϕV0/∂T2)P. The results showed that all the electrolytes act as structure-makers in these media. Also the compressibility data indicated electrostriction of the solvent molecules around the cations. The activation parameters of viscous flow were also determined and discussed by the application of transition state theory.

Volumetric, viscometric and acoustic studies of ternary systems of tetrahydrofuran + 1,3-dioxolane with monoalkanoic acids and their corresponding binaries

The excess molar volumes ( ), viscosity deviations ( ) and deviation in isentropic compressibilities ( ) have been calculated from the measured density, viscosity and speeds of sound data over the whole composition range for the ternary systems of tetrahydrofuran (THF) + 1,3-dioxolane (1,3-DO) + formic acid, acetic acid, propionic acid and butyric acid and the constituent binary mixtures of tetrahydrofuran or 1,3-dioxolne + formic acid, acetic acid, propionic acid, butyric acid and tetrahydrofuran or 1,3-dioxolne at 298.15 K under atmospheric pressure. The excess or deviation properties of the binary and ternary systems were fitted to Redlich–Kister and Cibulka equations, respectively. The excess or deviation properties are found to be either negative or positive depending on the molecular interactions and the nature of liquid mixtures.

Conductivity Study of Some Thiocyanate Salts in Aqueous Binary Mixtures of Tetrahydrofuran and 1,3-Dioxolane at 298.15 K

Abstract Electrical conductance measurements are reported for different thiocyanate salts, viz. ammonium thiocyanate (NH4CNS), sodium thiocyanate (NaCNS) and potassium thiocyanate (KCNS), sodium bromide (NaBr), sodium tetraphenylborate (NaBPh4) and tetrabutylammonium bromide (Bu4NBr) in different mole fraction of water-tetrahydrofuran (THF) and water-1,3-dioxolane (1,3-DXL) binary mixtures at 298.15 K. The conductance data have been analyzed by the Fuoss conductance equation in terms of the limiting molar conductance (Λ0), the association constant (KA) and the association diameter (R). The limiting ionic conductances have been estimated from the appropriate division of the limiting molar conductivity value of the “reference electrolyte” Bu4NBPh4. Slight ionic association was found for all these electrolytes in these solvent mixtures. The results have been interpreted in terms of the formation of ion-pairs of ion–solvent interactions and structural changes in the mixed solvents.