The apparent molar volumes (V 2, φ) have been determined for glycine, l-alanine, and l-leucine in water and in aqueous magnesium chloride solutions with concentrations ≈ (0.05 to 0.80) mol·kg-1 by measuring the densities at (288.15, 298.15, and 308.15) K. The apparent molar heat capacities (C p2, φ) have also been determined for glycine and l-alanine in aqueous magnesium chloride solutions with concentrations ≈ (0.05 to 0.40) mol·kg-1 by measuring heat capacities in the temperature range (298.15 to 328.15) K. These properties show a peculiar dependence upon the concentration of magnesium chloride. The standard partial molar volumes at infinite dilution ( ) obtained from these data have been used to calculate the partial molar volumes of transfer of amino acids from water to aqueous magnesium chloride solutions at infinite dilution (Δt ), which are positive for the presently studied amino acids at all temperatures and concentrations. The partial molar expansibilities (∂ /∂T) P at infinite dilution and the (∂2 /∂T 2) P values have also been determined from the data at various concentrations of the salt. The volumetric interaction parameters have been calculated from Δt data. The results have been discussed in terms of various interactions operating in these systems.

Precise density and viscosity measurements on aqueous solutions of lithium acetate, sodium acetate, potassium acetate, magnesium acetate, and calcium acetate have been carried out in the temperature range of T ) (288.15 to 318.15) K using a vibrating-tube digital densimeter and Micro-Ubbelohde type capillary viscometer, respectively. The data have been used to obtain partial molar volumes at infinite dilution, V 2 o , and viscosity B-coefficients for these salts. The effect of temperature on these thermodynamic properties has been studied by determining the partial molar expansibilities (∂V 2 o /∂T) P and (∂ 2 V 2 o /∂T 2 ) P and (∂B/∂T) coefficients. The activation free energies, ∆µ 2 0,+ , for the viscous flow of solutions have also been obtained by application of transition state theory to the viscosity B-coefficient data. The results have been rationalized in terms of various interactions taking place in these solutions.

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