Anomalous propagation and scattering of sound in 2-propanol water solution near its singular point

In this study we describe the anomalous physical properties of aqueous alcohol solutions near its singular (particular) points. A special attention is paid to conducting experiments on the temperature (T), concentration (x) and frequency (f) dependence of the sound velocity and effective absorption coefficient in a binary mixture 2-propanol - water in wide intervals of T = (293 ÷ 343) K, x = (0 ÷ 1) of 2-propanol molar fractions, and f = (10 ÷ 2500) MHz. A singular (particular) point of 2-propanol-water solution with coordinate xs = 0.03 ± 0.01, Ts = (313.0 ± 2.0)K is found as the intersection points of the sound velocity and absorption coefficient dependence on concentration and temperature at different frequencies. An anomalous behavior of aqueous alcohol solutions near the singular (particular) points enables us to support the hypothesis of the “fluctuating clusters mechanism”. This finding can directly explain two important effects as follows: an anomalous growth of (a) the light molecular scattering and (b) the sound molecular scattering.