Ultrasonic Studies of 4-Aminobutyric Acid in Aqueous Metformin Hydrochloride Solutions at Different Temperatures

Abstract

Ultrasonic speeds and density data of 4-aminobutyric acid in 0.05 M, 0.10 M, and 0.15 M aqueous metformin hydrochloride (MFHCl) solutions are measured at 308.15 K, 313.15 K, and 318.15 K. The isentropic compressibility (k _S ), the change in isentropic compressibility (Δk _S ), the relative change in isentropic compressibility (${\Delta k_S/k_S^0}$), the apparent molal compressibility (${k_\phi}$), the limiting apparent molal compressibility (${k_\phi^0 }$), the transfer limiting apparent molal compressibility (${\Delta k_\phi^0}$), the hydration number (n _H), and the pair and triplet interaction parameters (k _AH, k _AHH) are estimated. The above parameters are used to interpret the solute–solute and solute–solvent interactions of 4-aminobutyric acid in aqueous MFHCl solutions.