SURFACE-TENSION OF PENTAFLUOROETHANE (HFC-125)

A set of accurate surface-tension data for HFC-125 has been obtained e xperimentally with both an absolute capillary rise technique and a dif ferential capillary rise technique in the temperature range of 233.15- 333.15 K. The purity of the experimental HFC-125 sample is 99.98 wt%. The two sets of experimental results with an absolute capillary rise m ethod agree well with each other and, also, with the experimental resu lts with a differential capillary rise method. The absolute deviations of experimental results with these two methods are within 0.01 mN .m( -1.) The relative deviation are within 0.2%. A van der Waals surface-t ension correlation is also proposed.