Ultrasonic study of critical mixing of hexane and β, β′-dichloroethyl ether

The velocity and attenuation of ultrasonic waves in the critical temperature region of a binary mixture of hexane and β, β′-dichloroethyl ether have been measured at 1, 3, 5, 7, and 9 MHz. By assuming that the attenuation per wavelength is made up of two terms, αλ =Af−1/4+Bf, we obtain good agreement with the Fixman theory for both αλ and α/f2. The magnitude of B, however, is only partially accounted for by our measured values of shear viscosity.