The Volume, Adiabatic Compressibility, and Viscosity of Amino Acids in Aqueous Alkali-chloride Solutions

Abstract

Abstract The apparent molal volumes (φV), apparent molal adiabatic compressibilities (φKS), and relative viscosities (nr) at 25 °C have been obtained for the following amino acids in aqueous alkali-chloride solutions from measurements of the density, the ultrasonic velocity, and the flow time: glycine, l-alanine, β-alanine, α-aminoisobutyric acid, l-serine, and l-threonine. Viscosity measurements were also carried out in water for reference. The alkali chlorides used were lithium, sodium, and potassium chlorides. The limiting values φVo, φKSo and the extended Jones-Dole viscosity coefficients, B and D, were calculated by a linear extrapolation using the least-squares method. All the φVo, φKSo, and B values obtained in the mixed solvents were larger than the corresponding ones in water, except in a few cases of the B coefficient. The results are discussed in terms of the dehydration effect of the electrolytes upon the amino acids.