Molar heat capacity C-v, vapor pressure, and (p, rho, T) measurements from92 to 350 K at pressures to 35 MPa and a new equation of state for chlorotrifluoromethane (R13)

Measurements of the molar heat capacity at constant volume C-V for chlorotr ifluoromethane (R13) were conducted using an adiabatic method. Temperatures ranged from 95 to 338 K, and pressures were as high as 35 MPa. Measurement s of vapor pressure were made using a static technique from 250 to 302 K. M easurements of (p, rho, T) properties were conducted using an isochoric met hod; comprehensive measurements were conducted at 15 densities which varied from dilute vapor to highly compressed liquid, at temperatures from 92 to 350 K. The R13 samples were obtained from the same sample bottle whose mole fraction purity was measured at 0.9995. A test equation of stale including ancillary equations was derived using the new vapor pressures and (p, rho, T) data in addition to similar published data. The equation of stale is a modified Benedict-Webb-Rubin type with 32 adjustable coefficients. Acceptab le agreement of C-V predictions with measurements was found. Published C-V( rho, T) data suitable for direct comparison with this study do not exist. T he uncertainty of the C-V values is estimated to be less than 2.0% for vapo r and 0.5% for liquid. The uncertainty of the vapor pressures is 1 kPa, and that of the density measurements is 0.1%.