IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Glass Ball as Bullet Solubility System: 1-Pentanol with Hexane (n-hexane) and water

   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) 1-Pentanol (pentyl alcohol, amyl alcohol, n-amyl alcohol); C5H12O; [71-41-0]  NIST Chemistry WebBook for detail
   (3) Hexane (n-hexane); C6H14; [110-54-3]  NIST Chemistry WebBook for detail

   A. Skrzecz, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland (1995.09)

Critical Evaluation:

      A survey of reported compositions along the saturation curve (sat), and compositions of coexisting phases in equilibrium (eq.) for the system 1-pentanol-hexane-water is given in Table 83.

Saturation curve
   The ternary system 1-pentanol-hexane-water forms a miscibility gap of type 2. The system 1-pentanol-hexane is miscible. Two binary systems hexane-water and 1-pentanol-water, form miscibility gaps. Data for these binary systems were compiled and critically evaluated in previously published SDS volumes, Refs. 3 and 4, respectively. The recommended values of mutual solubility at 293 K are: for hexane-water system x"2=2.5·10–6 and x'2=0.999 47,3 and for 1-pentanol-water system x'1=0.679 and x"1=0.004 81.4 Solubility of water in hexane reported by Charykov et al.,1 (x'2=0.9996) is slightly smaller than the recommended value, Ref. 3 while the solubility of water in 1-pentanol (x'1=0.67), is in qualitiative agreement with Ref. 4. Similarly, the solubility of water in 1-pentanol at 298 K reported by Gorovits et al.,2 (x'1=0.0666), differs a little from that recommended in Ref. 4 (x'1=0.674). The differences are within experimental error. Equilibrium data of Gorovits et al.2 were taken into account during discussion of the binodal curve at temperature range 298.2-338.2 K and are self-consistent showing slightly increasing solubility with temperature. Solubility data of Charykov et al.1 at 293.2 K show a slightly higher solubility at high hexane concentrations than data of Ref. 2, measured at even higher temperatures. However, these differences are within the likely experimental errors. One experimental saturation point reported in Ref. 1,(x1=0.73, x2=0.016) appears to be in error. Both data sets are treated as tentative.

Phases in equilibrium
   Compositions of coexisting phases in equilibrium for the ternary system 1-pentanol-hexane-water were reported by Gorovits et al.2 at three temperatures 298.2, 318.2, 338.2 K as well as at isobaric conditions at the pressure 16.13 kPa. All tie lines constructed on the basis of experimental points are consistent with one another. The assumption made in Ref. 2, that the concentration of hexane in the water-rich phase is negligible may be acceptable because of the very low hexane concentrations and accuracy of analytical method. The equilibrium data are treated as tentative. As an example of the system behavior, the experimental data at 298.2 K, Ref. 2 are presented in Fig. 45 .

Experimental Data:   (Notes on the Nomenclature)

TABLE 83. Summary of experimental data for the system 1-pentanol-hexane-water
Charykov et al., 1978293sat. (7)1
Gorovits et al., 1986298-338eq. (39)2
View Figure 1 for this Evaluation

Table 83  Number of experimental points in parentheses.

References: (Click a link to see its experimental data associated with the reference)

   1  Charykov, A.K.; Tikhomirov, V.I.; Potapova, T.M., Zh. Obshch. Khim. 1978, 48, 1916-21.
   2  Gorovits, B.I.; Markuzin, N.P.; Lesteva, T.M.,Vestn. Leningr. Univ., Ser. 4: Fiz Khim. 4, 100 (1986).
   3  Shaw, D.G., ed., Solubility Data Series, Vol. 37, Hydrocarbons with Water and Seawater, Part I: Hydrocarbons C5 to C7 (Pergamon, New York, 1989).
   4  Barton, A.F. M., ed., Solubility Data Series, Vol. 15, Alcohols with Water (Pergamon, New York 1984).