Abstract

PAEZ, Manuel S; PEREZ, Dairo E  and  JULIO, Oscar L. Molecular interactions of aqueous sodium nitrate solutions from viscometric data. Rev.Colomb.Quim. [online]. 2016, vol.45, n.1, pp.21-26. ISSN 0120-2804.  https://doi.org/10.15446/rev.colomb.quim.v45n1.57200.

Flow times of aqueous sodium nitrate solutions in the molal concentration interval 0.0000 to 0.9996 (mol kg) were determined by using an automatic microviscosimeter AMVn Anton Paar^® at temperatures ranging from 283.15 K to 318.15 K every 5 K and atmospheric pressure of 0.101 MPa. From the data obtained, the dynamic viscosities (η), the viscosity coefficients A, B, and C form the Jones-Dole equation, dBIdT and the activation parameters of viscous flow (ΔG^∞‡, ΔH^∞‡ and ΔS^∞‡) at infinite dilution were calculated. The coefficients A, B, and C were positive as well as dBIdT. On the one hand, according to the sign analysis, sodium nitrate acts as a structure-forming solute of the water. On the other hand, the activation viscous flow parameters at infinite dilution (ΔG^∞‡, ΔH^∞‡ y ΔS^∞‡) revealed that the viscous flow process is endothermic with a clear ion-solvent interactions predominance.

Keywords : Binary mixtures; dynamic viscosity; activation parameters; Jones-Dole.

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