Abstract:

The infinite dilution activity coefficients γ_i, partial molar excess enthalpies H_i~E and entropies S_i~E of C_1—C_4 alcohols have been measured in C_(16)—C_(23) normal alkanes, squalane and squalene by gas-liquid chromatography。 The obtained infinite dilution activity coefficients are all greater than unity. In the same stationary Iiquid, the values of γ_i follow the order: methanol>ethanol>n-propanol>n-butanol; n-propanol>isopropanol; n-butanol>isobutano>sec-butanol>tert-butanol.
It has been found that the activity coefficient of the same alcohol in squalane is greater than in squalene. The excess enthalpy of normal alcohols is greater than isomeric alcohols about 1.5 kJ.mol~(-1). The measured partial molar excess enthalpies and entropies are all positive. A linear relationship have been observed between the H_i~E and S_i~E values of the alcohols in the aliphatic hydrocarbon solvents, the results of which can be represented as
H_i~E-431 S_i~E+1620 (J.mol~(-1))