Sciencemadness Discussion Board

Solvent Solubility Question

Gigtator - 23-6-2019 at 11:33

Hello everybody,

a quick question just came to my mind:

- So let us assume we have water as a polar solvent.
- It is mixed with isopropyl alcohol which has polar and nonpolar characteristics.

- If finally a non-polar & water insoluble solvent such as dichlormethane is added what will happen?

Will the three of them mix up forming a single layer, or is the dichlormethane pulling the alcohol away from the water so that a polar and a non-polar layer will form?

Thank you in advance for your answer.

Best Regards
Gigtator

unionised - 23-6-2019 at 11:41

It depends.
If there is lots of IPA then it will all mix.
If it's mainly DCM and water then there will be two layers.
And, just to make it a little more complex, the miscibility is also temperature dependent.

DraconicAcid - 23-6-2019 at 12:07

If you have benzene, ethanol and water, you get this phase diagram:
1517_Explain the Three Liquids - Ternary Phase Diagram.png - 7kB

Sadly, it doesn't have a scale, but it seems that it it's more than 40% ethanol, you will form one phase. If you have a little less than that, you'll have two phases- one that's mostly benzene and water, and one that's mostly alcohol and water. If you only have a little ethanol, you'll have one phase that's ethanol and benzene, and the other that's mostly water.

3phase.png - 7kB