- 作者: --
- 作者服務機構: Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi-110 025, India
- 中文摘要: Densities,ρ, viscosities, η, and refractive indices, nD of aqueous caffeine (0.5 M) and of solutions of amino acids, l-phenylalanine (Phe), l-tyrosine (Tyr) and l-histidine (His), (0.01-0.05 M) in aqueous-caffeine have been measured at 298.15, 303.15, 308.15 and 313.15 K. From these experimental data, apparent molar volume, limiting partial molar volume, and the slope, transfer volume, Falkenhagen coefficient, A, Jones-Dole coefficients, B, free energies of activation per mole of solvent, and per mole of solute, enthalpy, and entropy, of activation of viscous flow, and molar refraction were calculated. The results are interpreted from the point of view of solute-solvent and solute-solute interactions in these systems. It has been observed that there exist strong solute-solvent and weak solute-solute interactions in these systems. Further, the solute-solvent interactions decrease, whereas solute-solute interactions increase with rise in temperature. It is observed that these amino acids act as structure-makers in aqueous-caffeine solvent. The thermodynamics of viscous flow have also been discussed.
- 英文摘要: --
- 中文關鍵字: Density; Viscosity; Refractive index; Limiting partial molar volume; Amino acids.
- 英文關鍵字: --