Study of electrical conductivity for salt diclofenac potassium in water and water-methanol mixtures at different temperatures

Abstract EN

This paper traces the conductivity of diclofenac potassium salts in the low concentrations in water and mixtures of water and methanol (10%, 20% and 30% aqueous methanol) at different temperatures (288.15, 293.15, 298.15, 303.15 and 308.15 K).

The conductivity data were analyzed using the Lee-Wheaton conductivity equation to obtain the values of equivalent conductivity at infinite dilution “∧o”, association constants (KA), the association diameter (R) and Walden product (Λ0η0).

The results showed that diclofenac potassium salt behaves as weak electrolytes in the solvents used.

Moreover, standard thermodynamic parameters of the association (change value in: Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) were calculated and discussed.

The results showed that the values of molar conductivity, the distance parameter between the ions (R) and association constants (KA) increase with increasing temperature at the best fit value of the standard deviation (σ).

The thermodynamic results also indicated that the ion association process is endothermic (+ΔH) and spontaneous (- ΔG) and increasing degrees of freedom (+ΔS).