resumo
Ultrasonic velocity and density values of amino acids: L-alanine/L-proline/L-valine/L-leucine in 2.0 M aqueous KCl and 2.0 M aqueous KNO3 solutions have been measured for several concentrations of amino acids at different temperatures: 298.15,303.15,308.15,313.15,318.15 and 323.15 K Using ultrasonic velocity and density data, the thermodynamic parameters such as isentropic compressibility (kappa(s)), change in isentropic compressibility (Delta kappa(s)) and relative change (Delta kappa(s)/kappa(0)) in isentropic compressibility have been computed. The trends in the behaviour of kappa(s), Delta kappa(s) and Delta kappa(s/)kappa(0) with changes in the concentration of amino acids/zwitterions as well as in temperature have been discussed in terms of zwitterions-ions, zwitterions-water dipoles, ions-ions, ions-water dipoles intermolecular/interionic interactions operative in the said systems. (C) 2008 Elsevier B.V. All rights reserved.
palavras-chave
APPARENT MOLAR VOLUME; BINARY-LIQUID MIXTURES; REFRACTIVE-INDEX; AMINO-ACIDS; ADIABATIC COMPRESSIBILITIES; ULTRASONIC VELOCITY; NACL SOLUTIONS; T=298.15 K; WATER; GLYCINE
categoria
Chemistry
autores
Riyazuddeen; Khan, I
nossos autores
Imran Khan
Bolseiro de pós-DoutoramentoGrupos
agradecimentos
The authors are grateful to Professor Nurul Islam for his help in many ways and thankful to the Chairman, Department of Chemistry for providing the necessary facility required in this research project. One of the authors (IK) thanks UGC for awarding the UGC fellowship.