Isobaric Heat Capacity for Liquid 1-Chloro-1,1-difluoroethane and 1,1-Difluoroethane

The isobaric heat capacities (Cp) for liquid 1-chloro-1,1-difluoroethane (HCFC-142b) and 1,1-difluoroethane (HFC-152a) have been measured by means of flow calorimetry. For HCFC-142b, 31 C_P values have been measured at temperatures from 276 to 350 K and pressures from 1.0 to 3.0 MPa. For HFC-152a, 36 C_P have been measured at temperatures from 276 to 360 K and pressures from 1.0 to 3.2 MPa. The uncertainties are estimated as ±13 mK in temperature, ±3 kPa in pressure, and ±0.4% for most of the C_P measurements. The purity of samples used for both HCFC-142b and HFC-152a measurements was 99.95 mol %. Correlations of liquid C_P as a function of temperature and pressure have been developed for both refrigerants on the basis of the measurements.