Enthalpy of interaction of some electrolytes with dimethyl sulfoxide in water at 298.15 K

Abstract

Enthalpies of mixing in water of dimethyl sulfoxide with several alkali-metal halides, Ph ₄ PCl and NaPh ₄ B have been determined by flow microcalorimetry at 298.15 K. Enthalpic pair interaction coefficients, h _NE , of the virial expansion of the excess enthalpy were calculated. The coefficients are positive for NaF, KF, Ph ₄ PCl and NaPh ₄ B, and negative for the remaining alkali-metal halides. A linear correlation between h _NE and the anionic radius is observed. Gibbs energy and entropic pair interaction coefficients have been calculated from literature data. Single-ion pairwise coefficients have been obtained using the tetraphenylphosphonium tetraphenylborate reference electrolyte assumption.