Heats of solution of 1-nonanol, 1-decanol and 1-undecanol in cyclohexane at 298.15 K and 308.15 K

• Published in: Thermochimica acta 1990-07, Vol.164, p.211-225
• Main Authors: Paljk, Špela, Klofutar, Cveto, Domańska, Urszula
• Format: Article
• Language: English
• Subjects: Chemical thermodynamics; Chemistry; Exact sciences and technology; General and physical chemistry
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/0040-6031(90)80438-5

The enthalpies of solution of 1-nonanol, 1-decanol and 1-undecanol in cyclohexane were measured at 298.15 K. and 308.15 K. The experimental values of enthalpy changes per mole of solution as a function of solute mole fraction are given in the form of a second-degree polynomial. The hydrogen bond enthalpies of 1-alkanol molecules in the systems studied were obtained from the enthalpy changes per mole of solute at infinite dilution. In addition, the values of the relative molar enthalpy of the pure solutes, the relative partial molar enthalpy of the solutes and solvent, and the relative apparent molar enthalpy of the solutes were determined at 298.15 K and 308.15 K. On the basis of a semi-ideal model of associated solution, the practical molal osmotic coefficients and the molal activity coefficient of the solutes were calculated from the thermochemical data. The non-ideal behaviour of these systems was described by the excess thermodynamic functions of solution, as well as by the partial excess thermodynamic functions of solutes and solvent. The enthalpic pair interaction coefficients were determined in the sense of the McMillan-Mayer theory. The non-ideality of the investigated systems was also described on the basis of an association model with an extended series of multimers, assuming that each addition of monomer to the progressively growing oligomeric species is more difficult.