Volumetric properties under pressure for 1,2-dichlorofluoroethane (R141), 1-fluoro-1,1,2-trichloroethane (R131a), and 1,2-dichloro-1,1-difluoroethane (R132b)

The elTect of pressure on the volume of RI41, RI31, and RI32b is reported as volume ratios (the volume under pressure relative to its value at atmospheric pressure) at six temperatures covering the range 278.15 to 338.13 K and pressures up to 380 MPa for RI41 and RI31a. For RI32b the same temperature range has been used, but above its normal boiling point experimental arrangements have limited maximum pressures to below 300 M Pa, with some loss of accuracy. Densities have been measured at atmospheric pressure for each liquid. The experimental data have been used to calculate isothermal compressibilities, thermal expansivities, and iInternal pressures: the change in isobaric heat capacity from its value at atmospheric pressure has also been estimated. The volume ratios lbr all three compounds can be represeInted by a version of the Tait equation based on previously reported data for 1,2-dichloroethane and l,l,2-trichloroethane with the inclusion of allowances for the substitution in the former of chlorine or fluorine for the hydrogens on one of the carbons.