Rajesh Kumar Das

Apparent molar volume, viscosity B -coefficient, and adiabatic compressibility of tetrabutylammonium bromide in aqueous ascorbic acid solutions at T = 298.15, 308.15, and 318.15 K

Apparent molar volumes ϕν and viscosity B-coefficients for tetrabutyl ammonium bromide (TBAB) in (0.00, 0.05, 0.10, and 0.15) mol dm−3 aqueous ascorbic acid solutions have been determined from solution density and viscosity measurements at temperatures over the range 298.15 to 318.15 K as function of concentration of ascorbic acid solutions. In the investigated temperature range, the relation: ϕν0 = a0 + a1T + a2T2, have been used to describe the partial molar volume ϕν0. These results, in conjunction with the results obtained in pure water, have been used to calculate the standard volumes of transfer Δϕν0 and viscosity B-coefficients of transfer for TBAB from water to aqueous ascorbic acid solutions for rationalizing various interactions in the ternary solutions. The structure making or breaking ability of TBAB has been discussed in terms of the sign of (δ2ϕν0/δT2)P. An increase in the transfer volume of TBAB with increasing ascorbic acid concentration has been explained by Friedman-Krishnan co-sphere model. The activation parameters of viscous flow for the ternary solutions studied have also been calculated and explained 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.

Study on solution–solution interactions prevailing in some liquid mixtures by volumetric, viscometric and acoustic measurements

The densities and viscosities of eight ternary mixtures of 1,4-dioxane, N,N-dimethylformamide and monoalkanols; methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, amyl alcohol (1-pentanol) and iso-amyl alcohol are determined over the entire range of composition at 298.15 K. From the experimental observations, the viscous synergy and antagonism, synergic and antagonic interaction index are derived by the equations developed by Kalentunc-Gencer and Peleg and Howell, respectively. A power factor, Fη , has also been introduced here. Also, the speeds of sound of these ternary mixtures have been measured over the whole composition range at the same temperature and thus, the isentropic compressibility and excess isentropic compressibility have been evaluated from the experimental data. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding.

Studies on Solution Properties of Some Amino Acids in Aqueous Mixture of Catechol

Apparent molar volumes, V φ, viscosities, η, and apparent isentropic compressibilities, K φ, of glycine, L-alanine, L-valine and L-leucine in 0.05, 0.10, 0.15 mol Kg−1 catechol solutions have been determined at 298.15 K by measuring the densities, viscosities and ultrasonic speed of the above solutions respectively. The standard partial molar volumes, , standard volumes of transfer, , standard partial isentropic compressibilities, , transfer compressibilities, , hydration number, N w , of the amino acids have been calculated for investigating the various interactions in the ternary solutions. The linear correlation of partial molar volume and viscosity B-coefficients with increasing number of carbon atoms in the alkyl chain have been used to explain the contribution of charged end group ( , COO−) and the ‒CH2 group to . The results have been interpreted in the light of solute-solvent interactions in the mixed ternary solutions.