Volumetric properties under pressure for 1-fluoro-1,2,2-trichloroethane (R131) and 1,1-difluoro-1,2,2-trichloroethane (R122)

The elTect of pressure on the volume of R 131 and R 122 is reported for six temperatures covering the range 278.15 to 338.13 K and pressures up to 380 MPa. Densities at the same temperatures have been measured at atmospheric pressure for each liquid. The experinaental data have been used to calculate isothernml compressibilities, thermal expansivities, and iInternal pressures: the change in isobaric heat capacity from its value at atmospheric pressure has also been estimated. The modified Tait equation has been used to show that the volume ratios for both compounds can be combined with those lbr RI23 (2,2-dichlorol, l,l-trifluoroethane) and represeInted by a common equation.