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

Enthalpies of mixing in water of dimethyl sulfoxide with several alkali-metal halides, Ph4PCl and NaPh4B 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, Ph4PCl and NaPh4B, 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.