Tracer diffusion in polyatomic liquids. III

Abstract

Tracer diffusivities are reported for argon, krypton, xenon, methane, carbon tetrachloride, and tetraalkyltins (methyl, ethyl, n-propyl, and n-butyl) in normal octane, decane, and tetradecane for temperatures ranging from 25 to 160 °C. The diffusivities were measured by the Taylor dispersion method. With temperature-dependent solvent diameters fitted from the tracer diffusivity of one of the solutes, a rough-hard-sphere theory predicts well the observed tracer diffusivities of all the other solutes in n-octane and, at high temperatures, n-decane (60–160 °C) and n-tetradecane (100–160 °C). The data are well correlated by either the Arrhenius equation, a free-volume formula, or the Dμp-correlation.