Speeds of sound, isentropic compressibilities and excess molar volumes of an alkanol + cycloalkane at 303.15 K: II. Results for alkan-2-ols + cyclohexane and alkan-1-ols + methylcyclohexane and theoretical interpretation

Isentropic compressibilities κS, excess isentropic compressibilities κSE and excess molar volumes VE have been determined from measurements of speeds of sound u and densities ρ on binary mixtures of propan-2-ol, butan-2-ol, pentan-2-ol, and octan-2-ol with cyclohexane and of butan-1-ol, pentan-1-ol, hexan-1-ol, and heptan-1-ol with methylcyclohexane at 303.15 K over the whole mole fraction range. The values of VE for all the eight mixtures are positive and the values of VE decrease with the number of carbon atoms in alkanol. The values of κSE for all four alkan-2-ol + cyclohexane systems are positive while in case of alkan-1-ol + methylcyclohexane systems, positive values of κSE for butan-1-ol + methylcyclohexane decrease to negative values for heptan-1-ol + methylcyclohexane. The change of sign occurs between pentan-1-ol and hexan-1-ol. The experimental speeds of sound have been analysed in terms of Schaaffs’ collision factor theory and Jacobson’s free length theory while the excess molar volumes of alkan-1-ols + cyclohexane, alkane-2-ols + cyclohexane and alkan-1-ols + methylcyclohexane have been analysed in terms of associated solution theory with a Flory equation of state contribution described by Treszczanowicz and Benson [Fluid Phase Equilib. 23 (1985) 117] and Heintz [Ber. Bunsen. Phys. Chem. 89 (1985) 172].