VAPOR-PRESSURE OF 11 ALKYLBENZENES IN THE RANGE 10(3)-280 TORR, CORRELATION BY EQUATION OF STATE

Several improvements of a static device for measuring low vapor pressures are described by the authors : Installation of a second pressure gauge allowing the extension of the measurement field. More reliable checking of the whole apparatus temperature. Improvement of the system in order to eliminate vapors after measurements. In the new version, the apparatus allows reliable measurements in the range -30 < t-degrees-C < 190-degrees-C 10(-3) < P(sat)mmHg < 280. The uncertainty on temperature measured with a thermocouple is +/- 0.02-degrees-C. The apparatus was calibrated with naphtalene and checked with water. In the latter case the discrepancy between our values and the literature data is 0.4% in the range 5-280 torr and 2% for pressures lower than 5 torr. The device was used to measure vapor pressure of 11 alkylbenzenes. The results obtained are in agreement with the few available literature data. They were correlated with the ANTOINE equation and the CARRIER-ROGALSKI-PENELOUX equation.