Colussi, A. J.A. J.ColussiHUI-MING HUNGHoffmann, M. R.M. R.Hoffmann2018-09-102018-09-101999http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000079933500029&KeyUID=WOS:000079933500029http://scholars.lib.ntu.edu.tw/handle/123456789/348269We report degradation rates of chlorinated methanes, ethanes, and ethenesspanning the range of Henry's law constants 0.9 ≤ H/(atm M-1) ≤ 24.5in water solutions sonicated at f = 205, 358, 618, and 1078 kHz. First-order degradation rate constants, k-X, vary as k-X ∼ HX0.30±0.03 at all frequencies, change with f by less than a factor of 2 in this range, and peak at about 600 kHz for all species. We show that experimental rates are consistent with (1) complete decomposition of the solute contained in collapsing bubbles, (2) about 15% ultrasound power efficiency for transient cavitation, and (3) a rather flat N(Ro) ∝ Ron, n ∼ 0, initial radius bubble distribution under continuous sonication. The solute content of collapsing bubbles is composed of the equilibrated vapor at Ro, plus the amount incorporated by diffusion from the surrounding solution during the acoustically driven expansion from Ro to Rmax, the maximum radius attained prior to collapse. The finding that k-X's decline above 600 kHz is ascribed to the fact that increasingly smaller bubbles collapse at rates reaching a limiting value at sufficiently high frequencies.[SDGs]SDG6journal article10.1021/jp984272o2-s2.0-0001106793WOS:000079933500029