JefferyH
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Solvent miscibility of 3 different solvents, 2 miscible, one not?
Sorry for the vague title. I haven't been able to find a good answer for this question so I figured I would ask here.
In a system with 3 solvents:
Water - Miscible with methanol
Methanol - Miscible with water
Oil - Only miscible with methanol.
If these three are mixed together in equal volume quantities, what will the phase separation outcome be? Will there be two separate phases? Or will
the oil be mixed in with the water/methanol? If so, does the oil itself only interact with the methanol, and rarely actually contact the water?
How would this all play in with solvent caging, on a molecule level?
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DraconicAcid
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It depends. In this case, I would expect there to be two phases- one will be a mixture of water, methanol and a small amount of oil; the other will
be oil, methanol, and some water. If your third solvent was something less hydrophobic, such as ether or butanol, you'd probably get a one-phase
mixture.
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Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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JefferyH
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So for the sake of molecular interactions, is it a safe assumption that there will always be a greater amount of methanol coming into contact with
water than the oil? In other words, does a methanol cage form around the oil preventing it from contacting the water?
Is there some sort of general rule for how much methanol might be in each layer, seeing as methanol is entirely miscible with both of them?
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