Solubilities in the system comprising nitromethane and dodecanoic acid have been reported in three publications. Broughton and Jones1 carried out measurements of the mutual solubilities of (1) and (2) between 342 and 353 K by the synthetic method. Hoerr, et al.2 studied solubility of (1) and (2) between 293 and 345 K by synthetic method. Schmid, et al.3 determined the upper critical solution temperature by synthetic method. The upper critical solution temperature has been reported as 345.2 K,2 349.7 K,3 and 352.1 K.1 The experimental data, reported in Broughton and Jones1 and Hoerr, et al.,2 differed significantly in measured UCST what influences on the temperatures of mutual solubility. The UCST equal 349.6 K calculated on the bases of relationship in the series nitromethane - acids (described in the Introduction material to this volume "Relations of Solubility Data in Binary Systems Containing Nitromethane") was decided to be treated as tentative UCST for this system. Then the UCST and temperatures in each data set1,2 have been normalized according to formula:
Tnew = (T/Tc)expยทTc+sensitive.Those transformed data have been approximated by the equation based on scaling law (described also in the Introduction material to this volume "Relations of solubility data in binary systems containing nitromethane") and the following parameters have been adjusted:
a1 = 0.51556, a2 = 0.46080, b1 = 2.65838, and b2 = -3.17572(mean standard error of estimate was 0.0157).
As an approximation, xc1 = 0.823 and UCST = 349.6 K have been used. The mutual solubilities calculated by this equation may be treated as tentative in the opinion of evaluators. The results of calculations for the selected temperatures are presented in the following table. This relationship, together with all experimental points,1,2 is also presented in Fig. 36 .