Molecular Interaction Studies on N-Alkanols with DMA in Toluene at 303K

Abstract

The ultrasonic study of velocity, density and viscosity has been measured for the mixtures of n-alkanols, namely; 1-propoanol, 1-butanol and 1-pentanol in toluene with N-N dimethyl acetamide (DMA) at 303K. The experimental data have been used to calculate the acoustical parameters such as adiabatic compressibility (β), intermolecular free length (L_f), free volume (V_f), internal pressure (π_i) and acoustic impedance (Z). The excess values of the above parameters have also been evaluated and presented. From the present investigation, it is obvious that a weak molecular association was identified. Mixing of DMA with n alkanols causes dissociation of hydrogen bonded structures of n- alkanols. Also, further addition of DMA with the mixture not only causes dissociation of hydrogen bonded structures of n-alkanols but also a decrease in molecular association between toluene and n-alkanols is observed. The evaluated excess values predict weak molecular interactions existing between DMA-n-alkanols as well as toluene-n-alkanols.