Thermodynamic properties of CF and CF2 from molecular flow effusion and mass spectrometer investigations

Abstract

The reaction of CF₄ and C has been studied in the temperature range 1800–2500 K. Equilibrium data were obtained for species obtained in this temperature range by two techniques: (i) molecular flow effusion and (ii) effusion-mass spectrometry. Heats of formation were calculated from the reaction thermodynamics for the species CF(g), ΔH°_{f298 K}= 58 ± 1 kcal/mol, and CF₂(g), ΔH°_{f298 K}=–41.7 ± 0.4 kcal/mol (third law). The S°₂₉₈ of CF₂(g) is 58.9 ± 1.2 cal/deg. mol (second law). Calculations provided thermodynamic limits for the species CF₃(g) and C₂F₂(g).