Acoustical and Thermodynamical Investigations of Threonine in Aqueous Saccharide Solution at Different Temperatures

The data for density (ρ), viscosity (η) and ultrasonic velocity (u) of aqueous solutions of threonine with lactose monohydrate and sucrose have been measured as a function of amino acid concentration at different temperatures. Using these data various interaction parameters viz. adiabatic compressibility (β), molar hydration number (nH), apparent molar compressibility (φ_k), apparent molar volume (φ_v), limiting apparent molar compressibility, limiting apparent molar volume and their constants (S_k,S_v) and viscosity A and B coefficient of Jones-Dole equation. These parameters have been interpreted the molecular interactions in terms of solute-solute and solute-solvent interaction present in the given solutions. Free energies of activation of aqueous amino acids were obtained by application of the transition-state theory to the B-coefficient data and the corresponding activation parameters were given. The Redlich-Kister model was used to correlate the measured properties. It was found that in all cases, the experimental data obtained fitted with the values correlated by the corresponding models very well.