We report the thermodynamic properties of 1,1,1,2,3,3-hexafluoropropan
e (known in the refrigeration industry as R236ea or HFC-236ea) in the
temperature and pressure region commonly encountered in thermal machin
ery. The properties are based on measurements of the vapor pressure, t
he density of the compressed liquid (PVT), the refractive index of the
saturated liquid and vapor, the critical temperature, and the speed o
f sound in the vapor phase. The surface tension was determined from th
e capillary rise. From these data we deduce the ideal-gas heat-capacit
y, the saturated liquid and vapor densities, the equation of state of
the vapor phase, the surface tension, and estimates of the critical pr
essure and density. The data determine the coefficients for a Carnahan
-Starlings-DeSantis (CSD) equation of state. The CSD coefficients foun
d in REFPROP 4.0 database are based on these present measurements.