Thermodynamic properties of seven gaseous halogenated hydrocarbons from acoustic measurements: CHClFCF{sub 3}, CHF{sub 2}CF{sub 3}, CF{sub 3}CH{sub 3}, CHF{sub 2}CH{sub 3}, CF{sub 3}CHFCHF{sub 2},CF{sub 3}CH{sub 2}CF{sub 3}, and CHF{sub 2}CF{sub 2}CH{sub 2}F
- National Inst. of Standards and Technology, Gaithersburg, MD (United States)
Measurements of the speed of sound in seven halogenated hydrocarbons are presented. The compounds in this study are 1-chloro-,2,2,2-tetrafluoroethane (CHCIFCF{sub 3} or HCFC-124), pentafluoroethane (CHF{sub 2}CF{sub 3} or HFC-125), 1,1,1-trifluoroethane (CF{sub 3}CH{sub 3} or HFC-143a), 1,1-difluoroethane (CHF{sub 2}CH{sub 3} or HFC-152a), 1,1,2,3,3-hexafluoropropane (CF{sub 3}CHFCHF{sub 2} or HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (CF{sub 3}CH{sub 2}CF{sub 3} or HFC-236fa), and 1,1,2,2,3-pentafluoropropane (CHF{sub 2}CF{sub 2}CH{sub 2}F or HFC-245ca). The measurements were performed with a cylindrical resonator at temperatures between 240 and 400 K and at pressures up to 1.0 MPa. Ideal-gas heat capacities and acoustic virial coefficients were directly deduced from the data. The ideal-gas heat capacity of HFC-125 from this work differs from spectroscopic calculations by less than 0.2% over the measurement range. The coefficients for virial equations of state were obtained from the acoustic data and hard-core square-well intermolecular potentials. Gas densities that were calculated from the virial equations of state for HCFC-124 and HFC-125 differ from independent density measurements by at most 0.15%, for the ranges of temperature and pressure over which both acoustic and Burnett data exist. The uncertainties in the derived properties of the other five compounds are comparable to those for HCFC-124 and HFC-125.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 669890
- Journal Information:
- International Journal of Thermophysics, Vol. 18, Issue 1; Other Information: PBD: Jan 1997
- Country of Publication:
- United States
- Language:
- English
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