Effect of paracetamol in aqueous sodium malonate solutions with reference to volumetric and viscometric measurements

• Densities and viscosities of paracetamol in aqueous sodium malonate solutions measured.
• Apparent molar volume (ϕVϕV) and standard molar volume (ϕV0) determined.
• Viscosity B-coefficient was determined.
• Effect of molality, solute structure and temperature analyzed in terms of (ion + ion) and (ion + solvent) interactions.
• Paracetamol behaves as a long range structure maker.

Apparent molar volumes and viscosity B-coefficients for paracetamol in aqueous sodium malonate solutions were determined from solution densities and viscosities measured at T = (298.15 to 318.15) K and at pressure p = 101 kPa as a function of paracetamol concentrations. The standard partial molar volumes (ϕV0) and slopes (SV∗) obtained from Masson equation were interpreted in terms of (solute + solvent) and (solute + solute) interactions, respectively. Solution viscosities were analyzed using Jones–Dole equation and the viscosity A and B coefficients discussed in terms of (solute + solute) and (solute + solvent) interactions, respectively. The standard volume of transfer (ΔtϕV0) and viscosity B  -coefficients of transfer (ΔtBΔtB) of paracetamol from water to aqueous sodium malonate solutions were derived to understand various interactions in the ternary solutions. The activation parameters of viscous flow for the studied solutions were discussed in terms of transition state theory. The structure making or breaking ability of Paracetamol was discussed in terms of the sign of (dϕE0/dT)P.

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