# Given this liquid-liquid phase diagram, is the green line the nitrobenzene-rich phase?

The temperature-composition diagram for hexane and nitrobenzene at 1atm. The region below the curve corresponds to the compositions and temperatures at which the liquids form two phases. The upper critical temperature, $T_\mathrm{uc}$, is the temperature above which the two liquids are miscible in all proportions.

Am I right in assuming that the right side (green line) is the nitrobenzene rich phase? Is that always the case? Whichever one has the side with a mol fraction of 1 that side is more abundant? If you don't understand my question just tell me, and I'll clarify

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It shows that above the temperature $$T_{uc}$$, there is only one phase (the substances mix in any ratio). Below that temperature, there are two phases, with compositions shown by the solid lines. The horizontal line shows that if you try to make a mixture with a mole fraction of $$a$$ at the given temperature, you will get two solutions with mole fraction $$a'$$ and $$a''$$ instead. You can calculate the approximate ratio of the volumes using this technique.