CARMEL JOLICOEUR and GHYSLAIN LACROIX. Can. J. Chem. 54, 624 (1976). The density and specific heat of dilute aqueous solutions of various alcollols and polyols have been measured at 25 "C. Such measurements have been carried out for the following solutes : methanol, ethanol, 11-propanol, 11-butanol, isobutanol, s-butanol, rert-butyl alcohol, 11-pentanol. 3-pentanol, r~eo-pentanol, ethyleneglycol, 1,4-butanediol, 1,6-hexanediol, dimethyl-2,2-propanediol, l,l,l-tris(hydroxymethyl)ethane, and pentaerythritol.The limiting apparent molal volume +, O and heat capacities 4, O derived from these data exhibit some variations among the properties of isomers (e.g. branched vs. normal alkyl groups). but these variations cannot be conclusively attributed to specific effects in the hydration of the alkyl groups. On the other hand, the data allows one to derive group contributions to +, O and +,O, namely A+O(CH?) for the methylene group, A+O(OH) for the O H functional group and 14O(H) for the C-H of a terminal methyl group.The concentration dependence of +, and +, brings out some interesting new features. With most of the alcohols, +, decreases with concentration, in a way related to the degree of hydrophobicity of the alcohol. Solute-solute interactions contribute to reduce +, of the hydrophilic solutes, but the opposite effect is observed with the most hydrophobic alcohols.