Supersonic Velocity in Gases and Vapours. Part IX. Specific Heats and Dispersion of Supersonic Velocity in Organic Vapours

It has been shown that the recent results obtained by Railston for the supersonic velocity at lower temperatures are in agreement with the author’s results at higher temperatures in the case of benzene, ethyl alcohol and ethyl ether. The methyl alcohol and carbon tetrachloride vapours appear to have lost the vibrational specific heats below mo Kc/sec. In the case of benzene and carbon disulphide vapours the value of V0 and V1 or Vt at 90 ° are 200 m./sec, 208 m./sec. and 203 m./sec. and 216 m/sec respectively, the corresponding values of the specific heats are in agreement with the theoretical values calculated on the basis of the assumption that in the case of benzene, the deformation vibrational terms and in the case of carbon disulphide, both the deformation and longitudinal vibrational terms disappear from the acoustic cycle.The supersonic velocities in vapours of acetone, chloroform, methylene chloride and ethyl alcohol yield specific heat values, which are higher than those calculated from spectroscopic data on account of uncertain corrections due to saturation