A survey of reported compositions along the saturation curve and compositions of coexisting phases in equilibrium (eq.) for the system methanol-octane-water is given in Table 16.

Saturation curve The ternary system methanol-octane-water forms a large miscibility gap of type 2 covering the majority of the concentration triangle. Compositions along the saturation curves were not reported independently in the references; the saturation curves can be constructed on the bases of equilibrium compositions. Two binary systems, octane-water and octane-methanol, form miscibility gaps. The data for these systems were compiled and critically evaluated in previously published SDS volumes, Refs. 3 and 4 respectively. The recommended, Ref. 3, values of mutual solubility of octane-water system at 293 K⁴ are: x"₂ = 9.9·10^-8 and x'₂ = 0.9995. The mutual solubility of methanol-octane system at 293 K⁴ are: x"₁ = 0.944 and x'₁ = 0.105. The binary data reported by Budantseva et al.² are: x"₂ = 2.0·10^-7, x'₂=0.999 57 and x"₁ = 0.960, x'₁ = 0.155, respectively.

Phases in equilibrium Compositions of coexisting phases in equilibrium for the ternary system methanol-octane-water were reported in both references. The experimental procedure was reported only in Ref. 1. After separation, methanol was determined by reaction with phthalic anhydride; water - with the Karl Fischer reagent. The compositions of phases in equilibrium reported in Refs. 1 and 2 are consistent with one another, they are treated as tentative and those at 293.2 K are presented in Fig. 9 .