Ternary LLE at

instead of mixing two pure species, we mix three, we find more complex behavior  

If we mix three members of one homologous series (such as pentane, heptane, hexane or benzene, toluene, xylene) we would find that they are miscible, forming one liquid phase. 

If we mix three members of very different chemical types (such as water, benzene, mercury) we would find three separate liquid phases, each containing one of the species practically pure, containing less (often much less ) than 1 mol% of each of the other two. 

If we mix water, ethanol, and benzene, we would expect more complex behavior, because water and ethanol are totally miscible, and benzene and ethanol are totally miscible, but water and benzene, as discussed above, are practically immiscible. 

The most common way to present the experimental data for such systems [4] is shown in Table 11.4. The data in this table are redundant if we know two of the mol fractions we can calculate the third. But this is the common way of presenting such data. 

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