Viscous synergic behaviour and solvent–solvent interactions occurring in liquid mixtures of aqueous alkanols with some alkanoic acids

Abstract

The densities and viscosities of six ternary mixtures of the water, monoalkanols; 1-propanol, 2-propanol and monoalkanoic acids; formic acid, acetic acid and propionic acid are determined over the entire range of composition at 298.15, 308.15 and 318.15 K. From the experimental observations, the viscous synergy and synergy interaction index are derived from the equations developed by Kalentunc-Gencer, Peleg and Howell, respectively. The speeds of the sound of these ternary mixtures have been measured over the whole composition range at the same temperatures, and also the excess molar volumes, the isentropic compressibilities and excess isentropic compressibilities have been evaluated from the experimental data.

Keywords:

• synergy
• water–monoalkanol–acid system
• density
• viscosity
• ultrasonic speed

Acknowledgements

The authors are grateful to the departmental special assistance scheme under the University Grants Commission, New Delhi (No. F 540/27/DRS/2007, SAP-1) for financial support. L. Sarkar is also grateful to UGC Research Fellowship in Science Ref. UGC letter No. F.4 -1/2006 (X1 plan/BSR) for sanctioning a junior research fellowship and providing financial aid in support of this research work.