Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Densities and viscosities for the solutions of nicotinic acid in aqueous sodium malonate solutions with several molalities (msodium malonate = 0.000, 0.005, 0.010, 0.015 and 0.020 mol kg 1) of sodium malonate were determined at T = (298.15 318.15) K and at pressure p = 101 kPa. Apparent molar volume, standard partial molar volume, the slope, standard isobaric partial molar expansibility and its temperature dependence, the viscosity B-coefficient and solvation number, etc., were determined. Using the experimental data viscosity B-coefficients were further utilized to obtain the free energies of activation of viscous flow per mole of the solvents and of the solute. Effects of molality, solute structure and temperature on all these parameters were analyzed in term of ion ion and ion solvent interactions; results revealed that the solutions are characterized predominantly by ion solvent interactions and nicotinic acid behaves as a long-range structure maker.