Thermal Conductivity and Equilibrium Constant of the System N2O4⇌2NO2

An all-glass apparatus has been used to measure the thermal conductivity of the system N2O4⇌2NO2 by the thick-wire variant of the hot-wire method in a temperature range of 32°—90°C and up to a pressure of about 50 cm Hg. The apparatus is capable of measuring the equilibrium constant and the thermal conductivity of the system simultaneously. The experimental data have been discussed in the light of theories based on the assumption of local chemical equilibrium. The discrepancy between the experimental and the calculated values of the heat conductivity which is particularly large at the lower pressures shows the necessity of applying nonequilibrium heat transfer theory to interpret the data.