Solubilities in the system comprising acetonitrile (1) and methyl hexadecanoate (2) have been reported in three publications. Sedgwick et al.¹ studied the phase equilibrium of the liquid-liquid-solid system and the mutual solubility of (1) and (2) between 273 and 304 K by the synthetic method. Rusling et al.² determined the mutual solubility of acetonitrile and methyl hexadecanoate at 298 K by the titration method. Schmid et al.³ measured the upper critical solution temperature for binary solutions of acetonitrile and methyl esters of fatty acids.
The upper critical solution temperature has been reported as 303.2 K³ and 304.2 K.¹ These data are in reasonable agreement and thus their average value: UCST = 303.7 ±0.5 K is recommended. The corresponding critical solution composition has been calculated by evaluator as x_cl = 0.88 from the data of Sedgwicket al.¹
Monotectic equilibrium has been reported to occur at 296.5 K.¹
All experimental values reported in work¹ have been approximated by an equation based on the scaling law (described in the introduction to this volume) for which the following parameters have been derived:

a₁ = 0.2938, a₂= 0.8177, b₁ = -12.0761, b₂ = 7.2283

(mean standard error of estimate was 0.0063).
For this approximation x_cl and UCST values from Sedgwick et al.¹ have been used. In the opinion of the evaluator, the mutual solubilities calculated by this equation may be treated as tentative. The results of calculations for the selected temperatures are presented in the following table. This relationship together with experimental data^1,2 are also presented in Fig. 18.