Original scientific paper

Thermodynamics of the Association Reaction of Na+ and Br- Ions in (70, 80, 90, and 95 Mass per Cent) 2-Butanol + Water Mixtures

Ivo Tominić ; Laboratory of Physical Chemistry, Faculty of Technology, University of Split, Teslina 10, HR-21000 Split, Croatia
Vesna Sokol ; Laboratory of Physical Chemistry, Faculty of Technology, University of Split, Teslina 10, HR-21000 Split, Croatia
Ivica Mekjavić ; Laboratory of Physical Chemistry, Faculty of Technology, University of Split, Teslina 10, HR-21000 Split, Croatia

Abstract

Molar conductivities of NaBr electrolyte in 2-butanol + water mixtures (w_2-butanol = 0.7, 0.8, 0.9, 0.95 ) were mesaured in the temperature range from 288.15 to 308.15 K at 5 K intervals. By processing the obtained data using the conductivity equations after Fuoss-Hsia and Lee-Wheaton it was not possible to establish a reliable value for the distance of the ions in the ion-pairs formed (R). The processing was therefore repeated using the same equations with R = q_Bjerrum . The association constants (K_A) obtained by both equations at different temperatures enable calculation of the standard thermodynamic quantities (ΔH° and Δ S°) for the association reaction. The obtained thermodynamic quantities, together with the limiting molar conductivity (Λ₀), were compared with the analogous data from literature for HBr electrolyte in the same mixtures, and for NaBr electrolyte in t-butanol + water mixtures.

Keywords

Hrčak ID:

132381

URI

https://hrcak.srce.hr/132381

Publication date:

1.10.1998.

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