resumo
Density (rho) and ultrasonic velocity (u) values of glycine in 1 0 M aqueous KCl and 1 0 M aqueous NaCl solutions have been measured as a function of amino acids concentration at T=(298 15, 303 15, 308 15. 313 15, 318 15 and 323 15) K. Using the rho and u data, the thermodynamic parameters such as partial molal volume (phi(0)(v)), isentropic compressibility (kappa(s)). change in isentropic compressibility (Delta kappa(s)), relative change (Delta kappa(s)/kappa(0)) in isentropic compressibility and partial molal isentropic compressibility (phi(0)(k)), values have been computed The increase in partial molal volume with temperature is attributed to the volume expansion of hydrated zwitterions The phi(0)(v) and phi(0)(k) values of glyane in 1 0 M aqueous KCl and NaCl solutions are larger than the corresponding values in water The larger partial molal volumes of glycine in 1 0 M aqueous KCl and NaCI is ascribed to the formation of 'zwitterion-K(+)/Na(+)/C1(-)' and 'K(+)/Na(+)/Cl(-)-water dipole' aggregates in solutions The variation of kappa(s) Delta kappa(s) and Delta kappa(s)/kappa(0) with amino acid/zwittenons concentration and temperature is discussed in terms of zwitterions-ions, zwitterions-water dipoles, ion-ion. ion-water dipoles due to intermolecular/interionic interactions occurring in the systems (C) 2010 Elsevier B V All rights reserved
palavras-chave
PARTIAL MOLAR VOLUMES; ALPHA-AMINO-ACIDS; BINARY-LIQUID MIXTURES; ADIABATIC COMPRESSIBILITIES; CHLORIDE SOLUTIONS; REFRACTIVE-INDEX; HEAT-CAPACITIES; T=298.15 K; L-ALANINE; ULTRASONIC VELOCITY
categoria
Chemistry; Physics
autores
Riyazuddeen; Khan, I
nossos autores
Imran Khan
Bolseiro de pós-DoutoramentoGrupos