Enthalpy of interaction of tetra- n-alkylammonium bromides and CsI with dimethyl sulfoxide in water at 298.15 K

Abstract

Excess enthalpies in water of dimethyl sulfoxide (DMSO) with various electrolytes (CsI, Me 4NBr, Et 4NBr, Pr 4NBr, Bu 4NBr and Pen 4NBr) have been determined by flow microcalorimetry at 298.15 K. Enthalpic pair interaction coefficients, h NE, of the virial expansion of the mixing enthalpy were calculated. The interaction of DMSO with CsI, Me 4NBr, Et 4NBr gives negative and that with the remaining electrolytes gives positive coefficients. In the tetraalkylammonium series, h NE becomes increasingly positive when the number of carbon atoms in the hydrocarbon chain is increased.