Thermodynamic and transport studies on some basic amino acids in aqueous sodium acetate solution at different temperatures

Abstract

Ultrasonic velocity (<i>U</i>), density (<img src='http://www.niscair.res.in/jinfo/rho.gif' border=0>) and viscosity (<img src='/image/spc_char/Etta.gif' border=0>) of three amino acids namely l-arginine, l-lysine and l-histidine in aqueous sodium acetate solution (0.4 mol. kg^-1) as a function of composition at 298.15, 308.15 and 318.15 K, have been measured. Using these experimental values, the acoustical parameters such as adiabatic compressibility (<img src='/image/spc_char/beta.gif' border=0>), molal hydration number (<i>n</i>_H), apparent molal compressibility (<img src='/image/spc_char/phi.gif' border=0>_K), apparent molal volume (<img src='/image/spc_char/phi.gif' border=0>_V), limiting apparent molal compressibility (<img src='/image/spc_char/phi.gif' border=0>_K⁰), limiting apparent molal volume (<img src='/image/spc_char/phi.gif' border=0>_V⁰), the constants (<i>S</i>_K, <i>S</i>_V) and viscosity <i>B</i>-coefficient of Jones-Dole equations were calculated for all the three systems. These parameters have been thoroughly analysed and eventually emphasizing the possible molecular interactions in terms of structure-making and structure-breaking effects of the above amino acids in the solvent mixture