THERMODYNAMICS OF LIQUID-MIXTURES CONTAINING METHYL METHYLTHIOMETHYL SULFOXIDE .7. EXCESS-ENTHALPIES OF BINARY-MIXTURES BETWEEN METHYL METHYLTHIOMETHYL SULFOXIDE AND EACH OF TOLUENE, ORTHO-XYLENES, META-XYLENES, PARA-XYLENES AND 1,3,5-TRIMETHYLBENZENE AT 298.15-K

Excess enthalpies of five mixtures between methyl methylthiomethyl sulfoxide (MMTSO) and five methylbenzenes, i.e., toluene, o-xylene, m-xylene, p-xylene or 1,3,5-trimethylbenzene, have been determined at 298.15 K. All the mixtures show the positive enthalpy changes over the whole range of mole fractions. Excess enthalpies of MMTSO + methylbenzenes are smaller than that of corresponding dimethyl sulfoxide(DMSO) + methylbenzenes and are increased with the increase of the number of methyl groups in the methylbenzenes. Linear relationships are obtained between the number of methyl groups of methylbenzenes and the excess partial molar enthalpies of MMTSO and benzene, toluene, m-xylene and 1,3,5-trimethylbenzene at infinite dilution. © 1990.