In the preceding paper, we reported the values of model-free chemical potentials for aqueous methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 1-hexanol at 25°C over the entire compositional region. Using alcohol excess partial molar enthalpies, HEAL, determined earlier in this laboratory (Can. J. Chem. 74, 713 (1996)), we have calculated excess partial molar entropies for the alcohols, SEAL, where AL stands for an alcohol. We then calculated, numerically, the entropic interaction, SEALAL = N([Formula: see text]SEAL/[Formula: see text]nAL)p,T,nW, where nAL is the amount of AL, nW is the amount of H2O, and N is the total amount of solution. SEALAL signifies the effect of addition of AL upon the entropic situation of existing AL in solution. Using these quantities, the mixing schemes in aqueous alcohols have been studied. The earlier conclusions, which used HEAL and HEALAL alone, are confirmed. Furthermore, the order of the relative hydrophobic nature of alcohols is established from the behaviour of SEALAL and of HEALAL as methanol < ethanol < 2-propanol < 1-propanol. Key Words: aqueous alcohols, excess partial molar entropies, entropic interaction mixing schemes, hydrophobicity ranking.
Excess partial molar enthalpies of alkane-mono-ols in aqueous solutions
