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 ran ge from 410 to 484 K at densities between 201.21 and 980.39 kg m(-3) and fo r pressures up to 35 MPa using a high-temperature and high-pressure adiabat ic 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 C-V data were converted to the ITS-90. Th e liquid and vapor one-phase isochoric heat capacities, temperatures and de nsities at saturation were extracted from experimental data for each measur ed isochore. Some of the experimental data (T-S, rho (S)), C-V along isocho res and at saturation are compared with values derived from isobaric heat c apacity C-P, sound velocity W, and PVT measurements. The values of critical parameters for N2O4 are measured using quasi-static thermograms method. (C ) 2000 Elsevier Science B.V. All rights reserved.