IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Methanol with Cyclohexene and Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) Cyclohexene; C6H10; [110-83-8]  NIST Chemistry WebBook for detail
   (3) Methanol (methyl alcohol); CH4O; [67-56-1]  NIST Chemistry WebBook for detail

Evaluator:
   A. Skrzecz, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland (1996.04)

Critical Evaluation:

      A survey of reported compositions along the saturation curve (sat.) and compositions of coexisting phases in equilibrium (eq.) for the system methanol-cyclohexene-water is given in Table 5.

Saturation curve The system methanol-cyclohexene-water forms a large miscibility gap of type 1 covering the majority of the concentration triangle. Compositions along the saturation curves reported in both references were obtained by the titration method. Experimental data within each data set, measured at various temperatures, as well as between data sets, are consistent. Only one binary system, cyclohexene-water forms miscibility gap. Binary data of this system were compiled and critically evaluated in a previously published SDS volume.³ The recommended, Ref. 3, values of mutual solubility at 298 K are x'₂=0.9983 and x"₂=0.000 035. Budantseva et al.² report data of mutual solubility at 293.2 K which are almost equal x'₂=0.9981, x"₂=0.000 05. The saturation curves for both temperatures are located very closely to one to another, a temperature difference 5 K is not significant. Maximum methanol concentration on saturation curve is observed at the region close to x₁=0.78, x₂=0.14. All experimental data, reported 293 and 298 K in the two references are treated as tentative.

Phases in equilibrium Compositions of coexisting phases in equilibrium for the ternary system methanol-cyclohexene-water were reported in both references. After separation, phases in equilibrium were analyzed. Washburn et al.¹ reported that the hydrocarbon-rich phase did not contain water, which presumably was the result of analytical limitations (self constructed refractive index-composition curve). Budantseva et al.² used more precise analytical methods (glc-for methanol and cyclohexene and the Karl Fishcher - for water). Their results seem more reliable. The plait point of the system reported at 293.2 K,¹ was x₁=0.504, x₂=0.477. The miscibility gap of the binary cyclohexene-methanol system may exist at temperatures below 270 K, but this region was not studied in Ref. 4. The equilibrium data are treated as tentative. Experimental data of Budantseva et al.² at 293.2 K are presented in Fig. 2 .

Experimental Data: (Notes on the Nomenclature)

TABLE 5. Summary of experimental data for the system methanol-cyclohexene-water
Author	T/K	DataType	Reference
Washburn et al., 1940	298	sat. (16), eq. (7)	1
Budantseva et al., 1976	293	sat. (6), eq. (9)	2

View Figure 1 for this Evaluation

Notes:
Table 5  Number of experimental points in parentheses.

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

   1  Washburn, E.R; Strandskov, C.V., J. Phys. Chem. 48, 241 (1944)
   2  Mason, L.S.; Washburn, E.R., J. Am. Chem. Soc. 59, 2076 (1937).
   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  Shaw, D.G.; Skrzecz, A.; Lorimer, J.W.; Maczynski, A., eds., Solubility Data Series, Vol 56, Alcohols with Hydrocarbons (Pergamon, New York, 1994).