The Absorption of Sound in CO2, N2O, COS, and in CS2, Containing Added Impurities

Abstract

We have investigated the absorptive characteristics of CO2, N2O, COS, and CS2 as influenced by the addition of certain gases, such as H2, H2O, H2S, CH3OH, etc., acting as “catalysts.” These catalysts shift the absorption bands to higher frequencies; the magnitudes of these shifts yield information respecting (1) the frequency at which each pure gas has its maximal absorption, and (2) the nature of the molecular collisions involved, and especially the effectiveness of these collisions in disturbing the vibrational states of the absorptive molecules. The results indicate that at atmospheric pressure and 23°C the absorption maxima for pure CO2, N2O, COS, and CS2 are at 20 kc, 153 kc, 287 kc, and 379 kc, respectively. The shift in each case is proportional to the concentration of the added catalyst. The addition of one percent of H2O to CO2 shifts the absorption band for CO2 2250 kc; similarly, one percent of H2O shifts the CS2 band 2460 kc, the COS band 4200 kc, and the N2O band 427 kc. One percent of the other impurities produced shifts which varied from 6 to 1500 kc. Transition probabilities for the above gases have been calculated; the results will be discussed.