Physico-chemical behaviour of l-phenylalanine in aqueous and aqueous d-glucose solutions at different temperatures

Abstract

The density, d, viscosity, η, and the conductance, Λ, values of solutions of l-phenylalanine in aqueous and aqueous solutions of d-glucose (5, 10, 15, and 20wt%) have been determined at four different temperatures ranging from 298.15K to 313.15K at 5K intervals. Sound velocity has been measured at 298.15K. The experimental data were used to calculate apparent molar volume, Vφ, limiting apparent molar volume, Vφ°, apparent molar isentropic compressibility, Ks,φ, and limiting apparent molar isentropic compressibility, Ks,φ°. The derived acoustical and thermodynamics parameters, namely isentropic compressibility, Ks, specific acoustic impedance, Z, molar compressibility, W, molar sound velocity, R, free length, Lf, and relative association, RA, have been calculated. Shedlovsky equation has been used to obtain limiting molar conductance, Λm°, from the conductance data. The results have been discussed in terms of solute–solute, solute–solvent and solvent–solvent interactions.