Tuyển tập các báo cáo nghiên cứu khoa học trên tạp chí khoa học vật lý quốc tế đề tài: Volumetric and Thermodynamic Studies of Molecular Interactions in Ternary Liquid Mixtures at 303, 308 and 313K | Journal of Physical Science Vol. 20 2 97-108 2009 97 Volumetric and Thermodynamic Studies of Molecular Interactions in Ternary Liquid Mixtures at 303 308 and 313K AN. Kannappan1 S. Thirumaran2 and R. Palani2 department of Physics Annamalai University Annamalainagar 608 002 India department of Physics DDE Annamalai University Annamalainagar 608 002 India Corresponding author thirumaran64@ Abstract Ultrasonic velocity density and viscosity were measured for mixtures of 1-alkanols namely 1-propanol 1-butanol 1-pentanol and 1-hexanol with N N-dimethylformamide DMF in cyclohexanone at 303 308 and 313K. The experimental data were used to calculate the excess free volume Vf excess internal pressure nf and Gibb s free energy AG which were discussed in the light of molecular interaction existing in the mixtures. It was observed that the addition of DMF to mixtures caused the dissociation of the hydrogen-bonded structure of 1-alkanols. Furthermore the DMF-alkanol interactions were weaker than the alkanol-ketone interactions in the mixtures. Keywords alkanols ultrasonic velocity Gibb s free energy excess free volume Abstrak Halaju ultrasonik ketumpatan dan kelikatan telah diukur bagi 1-alkanol iaitu 1-propanol 1 1-butanol 1-pantanol dan 1-lexanol dengan dimetilformamida DMF dalam Cyclohexanone pada 303 308 dan 313 K. Data-data dari eksperimen telah digunakan untuk menghitung isipadu bebas berlebihan Vf tekanan dalaman berlebihan nE dan tenaga bebas Gibb AG yang telah didiskusi dalam interaksi molecular yang wujud di dalam mixtures . Telah diperhatikan bahawa penambahan DMF ke dalam mixtures telah mengakibatkan peleraian ikatan hidrogen struktur 1-alkanols. Interaksi DMF-alkanol lebih lemah daripada interaksi alkanol-ketone. Kata kunci alkohol halatuju ultrasonik tenaga bebas Gibb isipadu bebas lebihan 1. INTRODUCTION In recent years the measurement of ultrasonic velocity has been successfully employed in understanding the nature of molecular interactions in pure .
