THE EXCESS-ENTHALPIES OF (DINITROGEN OXIDE PLUS TOLUENE) AT THE TEMPERATURE 313.15-K AND AT PRESSURES FROM 7.60 MPA TO 15.00 MPA

The excess molar enthalpies HEm {xN2O + (1 - x)C6H5CH3} were measured in the vicinity of the critical locus and in the supercritical region. Mixtures at the temperature T = 313.15 K and at the pressure p = 7.60 MPa show very exothermic mixing. Mixtures at T = 313.15 K and p = 9.49 MPa show moderately exothermic mixing. Mixtures at 313.15 K and p = 12.27 MPa and 15.00 MPa show moderately endothermic and exothermic mixing in the toluene-rich region and dinitrogen-oxide-rich region, respectively. The changes observed in the excess enthalpy with pressure are discussed in terms of (liquid + vapour) equilibrium and critical constants for (dinitrogen oxide + toluene). © 1994 Academic Press Ltd.