Dissociation equilibrium of dinitrogen tetroxide in organic solvents: An electron paramagnetic resonance measurement

Abstract

The dissociation equilibrium of N2O4−NO2 has been measured in hexane, carbon tetrachloride and chloroform at different temperatures. The equilibrium constants at 298.15 K (25°C),K m (molality basis), are 3.5·10−5 in hexane, 5.9·10−6 in carbon tetrachloride and 5.3·10−6 in chloroform. The EPR technique has been used to quantify the NO2 radical. These data are compared with gas-phase and solution data of previous reports. The applicability of Hildebrand and Scatchard theory of solutions is also discussed and some thermodynamic properties are deduced, such as Henry’s N2O4 and NO2 constants in different solvents.