A survey of reported compositions along the saturation curve (sat.) and compositions of coexisting phases in equilibrium (eq.) for the system ethanol-cyclohexene-water is given in Table 20.

Saturation curve The system ethanol-cyclohexene-water forms a miscibility gap of type 1. 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 both data sets, are consistent. The experimental results at 228, 273, and 298 K in the paper of Washburn et al.¹ were expressed as the water tolerance of the alcohol-hydrocarbon mixture. Only one binary system, cyclohexene-water, forms a 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. Binary solubility data were not reported together with ternary data in any of the references discussed. Compositions of coexisting phases in equilibrium at 298.2 K, Ref. 1, are consistent with those measured along the saturation curve. Experimental results reported at lower temperatures by Kretschner and Wiebe² are in agreement with the general expectation, at lower temperature the solubility gap increases. The maximum ethanol concentration is observed on the saturation curve at 298.2 K. It was reported to be x₁=0.559 and x₂=0.157.

Phases in equilibrium Compositions of coexisting phases in equilibrium for the ternary system ethanol-cyclohexene-water were presented only in Ref. 1. The reported tie lines cover the whole range of miscibility gap. In the paper of Washburn et al.¹ two points reported for the hydrocarbon-rich phase did not contain water (x₂=0.9947 and x₂=0.9460). This presumably was the result of analytical limitations (self constructed refractive index-composition curve). Experimental compositions along the saturation curve and experimental compositions of coexisting phases in equilibrium at 298.2 K are treated as tentative and are presented in Fig. 11 .