Supersonic Measurement of the Heat Capacity of Propylene

Abstract

An apparatus designed for (1) a general study of acoustical dispersion in gases, and (2) measurement of gaseous heat capacities has been used to measure the heat capacity of propylene between 273 and 490°K. The general methods used are outlined and discussed. The measured heat capacity values agree well with those calculated from the frequency assignment as given by Wilson and Wells, and an assumed potential restricting rotation of about 2000 cal./mole, but deviate from the values calculated from Pitzer's frequency assignment and an 800-cal./mole potential. The measurements on propylene also have the value of serving as a test of the usefulness and practicality of the supersonic method of heat capacity determinations.

Speed of Sound Measurements Using a Cylindrical Resonator for Gaseous Carbon Dioxide and Propene

“…The present determined c p 0 is also in good agreement with the results of Chao and Zwolinski based on a statistical thermodynamic method. The measurements from Telfair agree well with the equation of state within 0.47 % from (270 to 350) K; most of the results from Kistiakowsky et al, Kistiakowsky and Rice, and Bier et al show deviations larger than 0.2 % from the equation of state …”

“…The measurements from a Relative uncertainty of the ideal gas heat capacity: U(c p 0 ) = 0.1 %; and uncertainty of the second acoustic virial coefficient U(β a ) = 0.5 cm 3 • mol −1 (level of confidence = 0.95). Telfair 79 agree well with the equation of state 72 within 0.47 % from (270 to 350) K; most of the results from Kistiakowsky et al, 80 Kistiakowsky and Rice, 81 and Bier et al 82 show deviations larger than 0.2 % from the equation of state. 72 3.3.…”

“…Relative deviations of c p 0 for propene from the equation of state developed by Lemmon et al: ○, this work; ◇, Chao and Zwolinski; □, Telfair; △, Kistiakowsky et al; ▽, Kistiakowsky and Rice; ☆, Bier et al …”