Volumetric and Viscometric Study of Dimedone in Ethanol-Water Mixtures

Abstract

Density and viscosity of binary (Dimedone-Ethanol) and ternary (Dimedone-Ethanol – Water) mixtures of Dimedone, Water and Ethanol were determined at various temperatures (298.15 to 318.15 K at 5 K intervals) in between a concentration range of 0.05 to 0.25 mol L-1 of Dimedone with a view to determining the molecular interactions among Dimedone, Water and Ethanol. Dimedone is an organic substance which has the applications in colorimetry, crystallography, luminescence and spectrophotometric analysis. And it can also be used for chemistry involving organic compounds of low electrical resistance. Ethanol is a colourless organic polar solvent has led to its largescale production in recent years with negligible toxicity. Ethanol is completely miscible with universal solvent water. So Ethanol– Water mixture can be a vital binary solution in investigating Dimedone that was taken as topic of research in this study. The apparent molar volumes, (φ ) were obtained from the experimental density data. In the Dimedone–Ethanol and Dimedone–Water–Ethanol system, the apparent molar volume of Dimedone increases. In addition, apparent molar volume at infinite dilution (φ ), apparent molar Expansivity and Sv (values of experimental slopes) were also calculated according to the experimental density data. The apparent molar volume at infinite dilution gives an idea about the presence of solutesolvent interactions whereas Sv is the experimental slopes which give an idea about the prevailing solutesolute interactions in the mixtures. The calculated data indicate that there may be solute-solute and solute-solvent interactions present in the binary and ternary solutions. It is seen that Dimedone has good structure making property in ternary solutions than the binary systems. Both binary and ternary systems shows rapid increase of viscosity values with the increased Dimedone concentration but the values of viscosity decreased with the increase of temperature. The viscosity data were employed to determine the viscosity coefficients (A&B), change of free energy, G*, change of enthalpy, H* as well as change of entropy, S*. From these thermodynamic parameters state of the spontaneity of the investigated systems were known. Moreover, positive A co-efficients and negative B co-efficients suggesting that strong solute-solute but weak solute-solvent interaction present in the binary and ternary solution. On the basis of this data, the predominant molecular interactions occurring between Dimedone-Ethanol and Dimedone–Water–Ethanol were found to be solute-solute interaction. The results suggest that there is a significant effect of Dimedone on Water and Ethanol.