Distribution coefficients in the water-dodecane system and the heats of adsorption of C1-C8 alcohols on silica

Distribution coefficients in the water-dodecane system and the heats of adsorption of C1-C8 alcohols on silica (Silochrom S-80) were determined by gas chromatography. At low temperatures, C1-C4 alcohols were largely distributed in the aqueous phase, and C6-C9 alcohols were predominantly dissolved in the organic phase; C5 alcohols had intermediate properties. Permittivity was found to correlate with log K d, which allowed us to predict the character of the distribution of alcohols in the water-oil system. The heats and isotherms of adsorption were determined for the alcohols studied. The heats of adsorption of alcohols on silica monotonically increased in the series under consideration. For C5-C8 alcohols, they exceeded the heat of adsorption of water. The isotherms of adsorption were described by the Freundlich equation.