liquid-liquid phase diagram

[KathChem82]

in a mixture of two volatile liquids. how do you separate the mixture into its two pure compounds?

[NanoMachine]

Fractional distillation, provided they have different boiling points. You adjust temperature and pressure to achieve separation.

[jeffy]

Of course, although it's not as common as distillation, you can also use fractional freezing. Seems people do this to increase the concentration of alcohol in some drinks. Also if you've got liquids that are potentially explosive or highly flammable, separation by freezing is a lot safer than by boiling!

[thor3436]

exactly!! how they separate helium from methane for party balloons is by freezing
all the methane since helium is a liquid at 2 degrees K
i bet if you where in a room that cold you would freeze in half a second

[NanoMachine]

Maxwell's Demon would be perfect.

[heidi]

If only he existed.

[jeffy]

Wouldn't Maxwell's Demon only work for two gases?

[NanoMachine]

No, he'll work for a liquid too. Molecules in a liquid can move around the liquid and be segregated by the demon, but more slowly than in a gas.