Solubilities in the system comprising nitromethane and 1-butanol have been reported in four publications. Mel'nikova and Zhuravlev¹ measured the mutual solubilities of the components between 275 and 291 K by the synthetic method. Sazonov and Filippov² studied mutual solubilities of (1) and (2) between 285 and 291 K, also using the synthetic method. Bittrich et al.³ determined the upper critical solution temperature and critical solution composition. Battler and Rowley⁴ reported the mutual solubility of the two components at 291.15 K.

Values obtained by the graphical interpolation or extrapolation from the data sheets are presented in Table 1. Data are "recommended" if two or more apparently reliable studies are in reasonable (±5% relative) agreement. All other data are regarded as tentative only.

The upper critical solution temperature has been reported as 290.5 K,¹ 291.14 K,² and 291.2 K³. Thus, the recommended value is: (290.9 ±0.3) K. The corresponding critical solution composition has been reported as x_c1 = 0.578,¹ x_c1 = 0.580,³ and x_c1 = 0.587². The average value, x_c1 = (0.582 ±0.004), is therefore recommended.

The recommended UCST and critical solution composition are consistent with the values calculated from the respective relationships in the nitromethane - alcohol series, discussed at the beginning of this volume (these calculated values are: UCST = 290.8 K and x_c1 = 0.587). The tentative and recommended values for the mutual solubility reported in the above tables have been approximated by the equation based on scaling law (described in the Introduction material to this volume "Relations of Solubility Data in Binary Systems Containing Nitromethane") and the following parameters have been adjusted:

a₁ = 0.84674, a₂ = 0.46931, b₁ = 3.01749, b₂ = -2.94053

(mean standard error of estimate was 0.0101).

For approximation, recommended values of UCST and x_c1 have been used. This relationship is presented in Fig. 23 together with experimental data reported in Refs. 1 and 2.