Fialho, PauloNieto de Castro, Carlos A.2013-09-162013-09-162000-03Fialho, Paulo; Nieto de C. C. A. (2000). "Prediction of the vapor pressure of environmentally acceptable halocarbons", «International Journal of Thermophysics», 21(2): 385-392. http://dx.doi.org/10.1023/A:1006631512597.0195-928X (Print)1572-9567 (Online)http://hdl.handle.net/10400.3/2253Copyright © 2000 Plenum Publishing Corporation.The vapor pressure and its dependence on temperature of halocarbons for 0.002< p R<1 have been analyzed in terms of universal behavior. Results for CFC-114, HCFC-123, HCFC-141b, HCFC-142b, HCFC-143a, HFC-23, HFC-32, HFC-134, HFC-125, HFC-134a, and HFC-152a for reduced temperatures between 0.55 and 1.0 show that the reduced vapor pressure can be expressed as a function of 1−T R by a Padé approximant. Deviations of the correlated data from the universal function do not amount to more than ±0.06 MPa, with an average deviation of 0.025 MPa. Predictions of the saturation vapor pressures of HCFC-124, HCFC-225ca, and HCFC-225cb, which are the systems used to test the capability of this scheme, agree within 0.025 MPa, that is, within the accuracy of the corresponding states correlation. However, for HFC-236ea, the deviations are as large as -0.07 MPa. The present scheme can be used to calculate the Pitzer acentric factor, and an average value of ω=0.269±0.015 is obtained for all the fluids.engHalocarbonsPredictionVapor PressureUniversal Correlationjournal article2013-08-09