Excess volumes and ultrasonic speeds for (di-n-propylether + n-heptane)

Thermodynamic study of (heptane+amine) mixtures. III: Excess and partial molar volumes in mixtures with secondary, tertiary, and cyclic amines at 298.15K

“…As the figure shows, the straight lines of linear alkanes and primary amines have the same slope. From literature data, we have calculated that also ethers [18,19], ketones [20][21][22], and alkanoates [22][23][24][25], show the same value of the slope. This clearly indicates a constant volume contribution by the methylene group CH 2 , whether it belongs to a hydrocarbon or to a monofunctional molecule.…”

“…Choosing the alkanes as reference molecules, the constant term A is identified as the intercept of the corresponding straight line in figure were evaluated in a previous work [2]. To obtain B j of O, CO, and COO we have used V calculated from V E,°o f ethers [18,19], ketones [20][21][22], and esters [22][23][24][25].…”

Dependence upon temperature of the excess molar volumes of tetrahydropyran + n-alkane mixtures

“…Predicted values of (aVE/aT),, and of the excess partial molar quantities ViE and (aViE/aT),, calculated for the system THP + n-heptane at 308. 15 For personal use only.…”

“…Densities of the pure liquids at the temperature of interest in this work, together with some values from the literature (3,(15)(16)(17)(18), are given in Table 1.…”

Thermodynamics of (1-alkanol+linear monoether) systems

“…Similarly, in (linear monoether + n-alkane), the sign of V E and A p depends on the relative size of the mixture components. For dipropylether + heptane, where the molecular sizes of both the components are similar and free volume effects are small, V E and A p are both positive over the whole mole fraction range [81]. In exchange, for systems containing longer monoether (dibutylether) and shorter alkane (hexane) molecules, free volume contributions are relatively more important, and both V E and A p are negative [82].…”