ULTRASONIC AND THERMODYNAMIC STUDIES OF TERNARY SOLUTIONS

Ultrasonic velocity and density of ethylene glycol in aqueous alkali c arboxylate solution of concentrations 0.5M, 1.0M and 1.5M at 308 K hav e been measured. The value of adiabatic compressibility (K-s), apparen t molar volume (phi(v)), apparent molar compressibility (phi(ks)) and hydration number (H-n) have been deduced from the ultrasonic velocity data. Results show that (i) there are short range weak interactions in ternary systems and (ii) the hydrophobic character decreases with inc rease in the size of ions and may be expressed in the order of CH3(CH2 )(3)COO- > CH3(CH2)(2)COO- > CH3CH2COO- > CH3COO- > HCOO- > Na+ > K+.