Thermodynamics of the solvation of non-electrolytes in C8 monofunctional organic solvents

Some results are reported concerning the enthalpies of solvation (ΔsolvH0) of some hydrocarbons (hexane, cyclohexane), ethers (tetrahydrofuran), ketones (cyclopentanone, pentan-3-one), alcohols (butan-1-ol, butan-2-ol), and water in octan-2-ol and hexylacetate. The ΔsolvH0 values were calculated by combining the calorimetric heats of solution here determined with the known enthalpies of vaporisation. In the investigated solvents, the enthalpies of solvation become less negative going from alcohols to ketones to ethers and to hydrocarbons. As regards alcohols and ketones, the ΔsolvH0 values are more differentiated in octan-2-ol than in hexylacetate. This reflects the different nature of the two solvents, amphiprotic the former and hydrogen bond acceptor the latter. The results are interpreted in terms of specific solute–solvent interactions.