Isochoric heat capacity measurements of nitrogen tetroxide system at temperatures between 410 and 484 K and pressures up to 35 MPa

The heat capacity of nitrogen tetroxide was measured in the temperature range from 410 to 484 K at densities between 201.21 and 980.39 kg m−3 and for pressures up to 35 MPa using a high-temperature and high-pressure adiabatic calorimeter. The measurements were performed in the one-phase region at 17 isochores (11 liquid and 6 vapor densities) including coexistence curve and critical region. Uncertainties of the measurements are estimated to be 2%. The original temperatures and CV data were converted to the ITS-90. The liquid and vapor one-phase isochoric heat capacities, temperatures and densities at saturation were extracted from experimental data for each measured isochore. Some of the experimental data (TS, ρS), CV along isochores and at saturation are compared with values derived from isobaric heat capacity CP, sound velocity W, and PVT measurements. The values of critical parameters for N2O4 are measured using quasi-static thermograms method.