Beschreibung:
The ultrasonic resonator interferometer has been used to measure the ultrasonic velocity at 30°C in 1,1-dichloroethane (ethylidene chloride, CH3CHCl2) and 1,2-dichloroethane (ethylene chloride,CH2Cl-CH2Cl) vapors as a function of frequency over pressure. The ranges f/p employed are 0.8 to 100 Mc sec−1 atmos−1 in the case of ethylidene chloride and 1.0 to 100 Mc sec−1 atmos−1 in the case of ethylene chloride. The velocities have been corrected for nonideality of the two vapors. Dispersion of ultrasonic velocity occurs in both the cases and this is ascribed to the slow rate of energy exchange between translational and vibrational states. There is evidence of double relaxation in the two cases, the principal f/p ratios at 30°C being 76.5 Mc sec−1 atmos−1 for the former and 102 Mc sec−1 atmos−1 for the latter.