and [EMIM][SCN] at 327.31 K determined by slow stirring
method as described in Section 3.2.3 as well as the methyl acetate
activity a1 in both homogenous and heterogeneous liquid ranges
determined by HSGC-EC technique. The a1(x1) plots for the two
methyl acetate(1) + IL(3) systems are shown in Fig. 6. This figure
reveals that the methyl acetate(1) + [BMPYR][DCA](3) liquid mixture,
although completely miscible at all proportions, is quite close
to liquid demixing and explains that normal ‘‘free’’ NRTL fitting of
these VLE data we tried first yielded parameters corresponding to
liquid phase instability. To avoid the artifact of ‘‘false heterogeneity’’
we applied rather than the ‘‘free’’ fitting, a constrained one
minimizing the objective function