The density, speed of sound and refractive index for (water + alkali metal) (Li, Na and K) were measured over their entire composition range at T = (298.15,303.15 and 308.15) K. The isentropic compressibility, change and relative change in isentropic compressibility, apparent molal compressibility, acoustic impedance, speed of light and molar refractions were calculated using values of the experimental density, speed of sound, and refractive index, respectively. Redlich-Kister smoothing linear equation was used for obtaining limiting sound velocity, isentropic compressibility and refractive index data. Ion-ion, ion-dipolar, solute-solvent and intermolecular interactions have been interpreted with thermodynamic properties. (C) 2013 Elsevier Ltd. All rights reserved.