All three binary pairs of components, nitromethane + 1-butanol, nitromethane + water and 1-butanol + water, are partially miscible. The data for first two systems were compiled and critically evaluated (Sazonov et al.³) and for 1-butanol + water system in Barton.⁴ The values of UCST (upper critical solution temperatures) of the binary systems are reported in Zhuravlev et al.¹ and Marigliano et al.² and presented in Table 2.
The solubility curve for the ternary system at 303.15 K was obtained by the titration method (Ref. 2) with an estimated accuracy in composition and temperature within ±0.0005 of mass fractions and ±0.05 K, respectively. The solubility temperatures of the liquid phases were determined (Refs 1 and 2) by the synthetic method in ternary mixtures with constant mass relationship of (1) and (2). The solubility curves at 283 K, 323 K, 343 K and 353 K (Ref. 1) and at 333.15 K, 340.15 K, 341.15 K, 348.15 K, 363.15 K and 388.15 K (Ref. 2) were constructed by graphical interpretation of the cloud-point data. Experimental errors were reported in Ref. 2 to be ±0.1 K (temperature) and ±0.001 mass fractions (solubility). Depending on temperature the system nitromethane + 1-butanol + water forms a miscibility gaps of Type I to III, Ref. 5. In the temperature range 273 K to 290.5 K (Ref. 1), where the three binary systems are partially miscible, the solubility curves correspond to Type III (Ref. 5). A three-phase region occurs below 281 K (Ref. 1). Above 281 K two separate regions of immiscibility exist, one of which can be described by band type curves. In the temperature range 290.5 K to 377.7 K (Ref. 1) or at 384 K (Ref. 2), where two binary systems nitromethane + water and 1-butanol + water partially miscible, the solubility curves correspond to Type II (Ref. 5), while 2 separate solubility curves can be clearly observed above 341 K.
Below this temperature there are band type curves. Above 384 K this ternary system has only one partially miscible region, Ref. 2. Solubility data at 303.15 K, 333.15 K, 348.15 K and 388.15 K are described by corresponding algebraic equations (Table 3). These smoothing equations give smaller standard deviations than any other tested equation. The equation parameters were calculated by the least squares method.
The solubilities calculated by the proposed equations are presented in Figs. 13 and 14 and in Table 3. Experimental solubility data, Refs 1 and 2, are presented in Figs. 13 and 14 for comparison.
LLE data for the ternary system nitromethane + 1-butanol + water were reported at 273.2 K, 281.2 K and 323.2 (Mel'nikova¹) in graphical form and at 303.15, 333.15, 341.15, 348.15 and 363.15 (Marigliano et al.²). Composition of each phase (Mel'nikova¹ and Marigliano et al.²) was calculated from the index of refraction-composition curve of saturated mixtures prepared at the time of the saturation curve measurements and also from the density-composition curve in Marigliano et al.² The compositions of three coexistent liquid phases at 273 K (Mel'nikova¹) are presented in graphical form. Plait points were reported in Marigliano et al.² at 340.5 K, 341.15 K, 348.15 K and 363.15 K. Experimental errors were reported in Marigliano et al.² as ±0.005 of mass fractions.

Solubility and liquid-liquid equilibrium data measured by different methods are in agreement with one another. Experimental data on solubility at some temperatures Mel'nikova¹ and Marigliano et al.² are presented in Figs. 13 and 14 in mole fractions. In view of the inaccurate results obtained in Mel'nikova¹ and Marigliano et al.² for the binary nitromethane + water, nitromethane + 1-butanol and 1-butanol + water systems, the evaluator considers the ternary system data to be tentative and concludes that new studies on the ternary system would be of value.