EFFECT OF DISSOLVED-GASES ON THE DENSITIES OF HYDROCARBONS

Measurements have been made, using a vibrating tube densitometer, of t he effects of dissolved air, nitrogen, oxygen, hydrogen, methane, and carbon dioxide on the densities of liquid hydrocarbons at 298.15 K and a total pressure of 101060 Pa. The hydrocarbons were heptane, octane, nonane, decane, dodecane, tetradecane, hexadecane, cyclohexane, methy lcyclohexane, and methylbenzene (toluene), Saturation of the liquids w ith gases other than carbon dioxide decreases the density by amounts r anging from about 0.004% for oxygen in hexadecane up to about 0.18 for methane in heptane. Saturation with carbon dioxide increases the dens ities by a maximum of almost 0.1%. For all gases, values of \Delta rho \ decrease with increasing carbon number in an approximately linear ma nner in the alkane series. Partial molar volumes of the gaseous solute s have been calculated by combining the density results with literatur e gas solubility data.