Author:
Ali A.,Shahjahan Shahjahan
Abstract
Abstract
Densities, ρ and viscosities, η for L-serine, L-threonine, L-glutamine, L-lysine, L-arginine and L-histidine (0.05–0.25 m) in 0.20 m aqueous tetramethylammonium bromide were determined at 298.15, 303.15, 308.15, and 313.15 K. The density data was used to compute apparent molar volume, φ
v
. The partial molar volume, φ
v
0, at infinite dilution and experimental slope, S
v
*
were obtained from Masson´s equation and interpreted in terms of solute-solvent and solute-solute interactions, respectively. The φ
v
0 values are found to vary with temperature as a power series of temperature. The structure-making/-breaking ability of solute were discussed using Hepler´s criterion. The partial molar volumes of transfer, φ
v
0
(tr) of amino acid from aqueous to aqueous tetramethylammonium bromide solution were interpretedin the light of cosphere overlap model. The viscosity data was utilized to determine A- and B-coefficients of viscosity, free energy of activation of viscous flow, Δμ
1
0
* and Δμ
2
0
*, per mole of solvent and solute, respectively, and ΔH
*
and ΔS
*
were also evaluated. The linear variation of φ
v
0 and B-coefficient with the number of carbon atoms in the alkyl chain of amino acids was utilized to determine the respective contributions of (NH3
+, COO–) and CH2 groups to φ
v
0 and B-coefficient, respectively.
Subject
Physical and Theoretical Chemistry