Volumetric, viscometric, and refractive index behaviour of α-amino acids and their groups’ contribution in aqueous d-glucose solution at different temperatures

Abstract

Density, ρ, viscosity, η, and refractive index, n D measurements have been carried out on α-amino acids, glycine, dl-alanine, l-serine, and dl-valine (0.1 to 0.5) M in 0.2 M aqueous d-glucose solution at T = (298.15, 303.15, 308.15, and 313.15) K. These measurements have been performed to evaluate some important parameters, viz, apparent molar volume, ϕ v, limiting apparent molar volume, ϕ v ∘ transfer volume, ϕ v ∘ ( tr ) , viscosity A and B-coefficients of Jones–Dole equation, variation of B with temperature, d B/d T, free energy of activation per mole of solvent, Δ μ 1 ∘ # , and solute, Δ μ 2 ∘ # , respectively, and molar refractive index, R D. These parameters have been interpreted in terms of solute–solute and solute–solvent interactions and structure making/breaking ability of solutes in the given solution. In addition to this, ϕ v ∘ , B-coefficient and Δ μ 2 ∘ # , have been split into group contributions NH 3 + , COO - , and CH 2 of the amino acids using their linear correlation with number of carbon atoms in the alkyl chain of the amino acids.