Heats of mixing for binary systems: n‐Alkanes + n‐Alcohols and n‐Alcohols

Abstract

Heats of mixing for 21 ternary systems of one n‐alkane + two n‐alcohols are reported at 25°C. Evaluation of four equations permitting the prediction of heats of mixing of ternary systems from binary data is made. Scatchard's modified equation for systems containing a polar component was found to be the most accurate.

Excess molar heat capacities for (decan-1-ol+n-heptane) at temperatures from (290 to 318)K. Experimental results and theoretical description using the ERAS model

“…The heats of mixing of (decan-1-ol + n-heptane) mixtures are positive, i.e., the mixing process is endothermic; the curves of the excess heat of mixing vs. mole fraction are asymmetric [24][25][26][27]. For mixtures of this type, the heat of mixing increases with increasing temperature.…”

“…However, the contribution to the heat of mixing, resulting from the break down of the hydrogen bonds, should decrease with increasing temperature since there are fewer hydrogen bonds to be broken. Consequently, the contributions to the heat of mixing from all other effects not related to the disrupter of hydrogen bonds increase with temperature [24]. According to the ERAS model the chemical contribution to the excess molar enthalpy increases with temperature and is prevailing in the whole temperature range studied (figure 3).…”

“…As , and 318.15 K (c) of (decan-1-ol + n-heptane) mixtures. Points -experimental data: h, reference [24]; n, reference [26]; s, reference [27]; --, ERAS model; Á Á Á Á Á Á, chemical contribution; and -----, physical contribution. results from the ERAS model calculations for (decan-1-ol + n-heptane) mixtures, the chemical contribution to the excess molar volume, V E m , is small and positive, while the physical contribution is negative and predominating.…”

“…The X AB parameter values are listed in table 8. The excess molar enthalpies for the temperatures of the measurements are available in the literature [24][25][26][27], but, unfortunately, they are not consistent. Moreover, an average value of the association volume, Dm* = À5.6 AE 10 À6 m 3 mol À1 [22], has been used in the calculation of the excess molar volumes by the ERAS model.…”

Correlation of measured excess enthalpies of binary systems composed of n-alkane+1-alkanol

“…The total flow rate was kept constant (0.7 ml/min) while the flow rates of each component in the binary systems were varied. The consistency of the measurements was verified by comparing with literature data for n-octane+ethanol system at 298.15 K [13,14]. The measured data were compared and they showed fair agreement with literature data as shown in Fig.…”