Exploring the Effect of Ammonium Acetate on Volumetric, Viscometric and Conductive Properties of l-Aspartic Acid in Aqueous Medium at Different Temperatures

Abstract

Study of some physicochemical properties of l-aspartic aid in water and aqueous ammonium acetate has been undertaken for this investigation. Density, viscosity and conductivity of the solutions were measured at different temperatures. Volumetric parameters such as apparent molar volume \(({V}_{\Phi })\), partial molar volume \(({V}_{\Phi }^{0})\), partial molar expansibility \(({E}_{\Phi }^{0})\) and Hepler’s constant \(({{\partial }^{2}{V}_{\Phi }^{0}/{\partial T}^{2})}_{{p}})\) and viscometric parameters such as relative viscosity\({(\eta }_{r })\), viscosity coefficients \({(B}_{J }\mathrm\,{\text{and} }\,{ A}_{F})\), Gibbs free energy of activation of viscous flow of solvent and solute \({(\Delta \mu }_{1}^{\#,0}\mathrm\,\text{ and }\,{\Delta \mu }_{2}^{\#,0})\) respectively) and corresponding change in enthalpy \({\Delta H}_{2}^{\#,0}\) and entropy \({\Delta S}_{2}^{\#,0}\) have been derived from the experimentally measured density and viscosity values. Variation of these parameters with concentration and temperature was analysed in the light of ion–ion and ion–hydrophilic interactions. The possibility of ion pair formation and its effect on migration of charged particles in solution have been determined by analysing the molar conductance (Λ_m), association constant \({(K}_\text{A})\), Walden product and thermodynamic functions. These parameters were qualitatively correlated with changes in structure of water that occurs when l-Aspartic acid interacts with ammonium acetate in aqueous media.