Behavior of Isobaric Heat Capacity of Pentafluoroethane in the Gas Phase

The isobaric specific heat capacity c p of gaseous pentafluoroethane was measured and the behavior was presented. With a flow calorimeter, 29 c p data of pentafluoroethane were measured at temperatures T from (303 to 343) K and at pressures p from (0.5 to 2.4) MPa. Some of them were measured in the immediate vicinity of the saturation curve. The expanded uncertainties (k = 2) of the temperature measurements U(T) and the pressure measurements U(p) are estimated to be below 50 mK and 11 kPa, respectively. That for c p measurements U c(c p) is assessed to extend from (14 to 60) J·kg–1·K–1. Then, the c p measurements including the previous 12 measurements were compared with some available equations of state. Using these confirmed data, the c p behaviors of gaseous pentafluoroethane were presented in a c p–p diagram.