Speed-of-sound measurements and ideal-gas heat capacity for 1,1,1,2-tetrafluoroethane and difluoromethane

Tsutomu Hozumi, Haruki Sato, Koichi Watanabe

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The speed of sound in gaseous 1,1,1,2-tetrafluoroethane (R-134a, CF3CH2F) and difluoromethane (R-32, CH2F2) has been measured by using a spherical resonator. The measurements for R-134a have been carried out along two isotherms at 323 K and 343 K and at pressures up to 400 kPa for a total of 26 values. For R-32 the measurements were made at 308 K, 323 K, 333 K, and 343 K and at pressures up to 500 kPa for a total of 44 measurements. The experimental uncertainties for R-134a in temperature, pressure, and speed of sound are estimated to be not greater than ±6 mK, ±0.2 kPa, and ±0.0061%, respectively. The experimental uncertainties for R-32 in temperature, pressure, and speed of sound are estimated to be not greater than ±8 mK, ±0.2 kPa, and ±0.0061%, respectively. The purities of the R-134a and R-32 samples were better than 99.95% and 99.99% of area percent of the gas chromatography, respectively. We have determined the ideal-gas heat capacities and the second acoustic virial coefficients from the speed-of-sound measurements.

Original languageEnglish
Pages (from-to)1187-1190
Number of pages4
JournalJournal of Chemical and Engineering Data
Volume41
Issue number5
DOIs
Publication statusPublished - 1996 Jan 1

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

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