Isobaric Heat Capacity Measurements for Dimethyl Ether and 1,1-Difluoroethane in the Liquid Phase at Temperatures from 305 K to 365 K and Pressures up to 5 MPa

Abstract

The isobaric heat capacity of dimethyl ether and 1,1-difluoroethane in liquid phase were measured at temperatures from 305 K to 365 K and pressures up to 5 MPa. A heat conduction calorimeter was applied in the measurements and a total of 81 data points for dimethyl ether and 78 data points for 1,1-difluoroethane were obtained. The uncertainties of measured heat capacity were estimated to be 2.1% for dimethyl ether and 1.8% for 1,1-difluoroethane, respectively. To reproduce the experimental data, a uniform equation was proposed. The equation showed average absolute deviations of 0.17 % for dimethyl ether and 0.30 % for 1,1-difluoroethane from the experimental values. Saturated liquid heat capacities for both experimental subjects were also obtained by extrapolating the equation to saturated pressures. Finally, comparisons have been done between our experimental data and literature data and fundamental equation of states.