Compressed Liquid Densities, Saturated Liquid Densities, and Vapor Pressures of 1,1-Difluoroethane

The compressed liquid densities and vapor pressures of 1,1-difluoroethane (HFC-152a) have been measured, correlated, and compared with other data. The liquid densities were measured with a combined standard uncertainty of ±0.05% using a vibrating tube densimeter over a temperature range of 243 K to 371 K and at pressures from near the saturated vapor pressure to 6500 kPa; thus the data extend nearly to the critical point ( T c = 386.41 K and P c = 4514.7 kPa). The vapor pressures were measured with a combined standard uncertainty of ±0.02% using a stainless steel ebulliometer in the temperature range from 280 K to 335 K. Saturated liquid densities were calculated by extrapolating the compressed liquid isotherms to the saturation pressure.