Ultrasonic absorption properties of solutions. Part 8.?(i) Diethylamine + water mixtures (ii) ultrasonic absorption and miscibility curves for some mixtures of water + t-butyl alcohol + t-amyl alcohol

Abstract

(i)[Blandamer, Hidden and Symons] The ultrasonic absorption properties are reported for mixtures of diethylamine + water, methyl alcohol, and t-butyl alcohol. Mixtures of diethylamine + water show intense excess abosorptions and this has been measured at 0 and 25° and over the frequency range 1.5–230 MHz. The variation of α/f2 with frequency for mixtures where the mol fraction of amine is between 0.05 and 0.25 is analyzed using two relaxation frequencies. The behaviour is compared with ultrasonic data for water + monohydric alcohol mixtures. (ii)[Blandamer, Hidden and Treloar] The mutual solubility curve for mixtures of water +(40 mol % t-amyl alcohol + 60 mol % t-butyl alcohol) has a lower critical solution temperature and closely resembles the curve for the ultrasonic absorption against mol fraction of water. The ultrasonic absorption αf2 at a fixed frequency f and composition decreases initially with increase in temperature but then increases as the critical temperature is approached. The absorption for a given mixture depends on f–5/4.