Ultrasound absorption in acetic acid-tetrachzoromethane mixture

Abstract

Abstract Absorption of ultrasonic waves has been investigated in the mixture of acetic acid and tetrachloromethane covering the complete concentration range. Measurements have been carried out at 20, 30 and 40°C within a frequency range from 3 to 57 MHz for strongly absorbing mixtures (rich in acetic acid) and 5–57 MHz for mixtures with lower absorption. At about 0.01 mole fraction of acetic acid a relaxation has been observed with a relaxation frequency of 20 MHz increasing rapidly with increasing concentration, so that its observation has become impossible at mole fractions of acid bigger than 0.07. At higher acid concentrations the well known low frequency relaxation has been observed. The relaxations are discussed in terms of coupled dimerization and cyclization reaction of acetic acid including the nonideality of the mixture. In this model the faster relaxation seems to be caused by the dimerization reaction.