LIGHT SCATTERING OF A CRITICAL BINARY LIQUID MIXTURE: TRIETHYLAMINE–WATER

Abstract

The coexistence curve and critical opalescence of a binary liquid mixture, triethylamine–water, have been reinvestigated. The measurements showed that the coexistence curve appears to follow a cubic relation to within about 0.003° of the critical solution temperature, and in this range, there is no evidence of a flat region. Furthermore, within the range of the values of s/λ(where s = 2 sin (θ/2), λ = wavelength in the medium, and s/λ varied from 1.2 × 10⁻⁴ to 7.0 × 10⁻⁴ Å⁻¹) and temperatures studied, the light scattering data are in good agreement with the Debye theory (J. Chem. Phys. 31, 680 (1959)). The molecular interaction range of Debye was found to be 5.1 ± 0.3 Å.