An unknown sample was given to me which had 2 compounds in it. The goal of the e

Question

An unknown sample was given to me which had 2 compounds in it. The goal of the experiment was to identify both compounds. The unknown that was given to me was a solid so I had to seperate both compounds using a seperatory funnel. Solids were formed in both the neutral and base samples. When it was time to recrystallize both of them, the neutral sample was recrystallized correctly however the solvent used for the base was wrong. I used ethanol instead of water, and when it was time to cool down the sample to recrystallize, no crystals were formed. So i added water to the sample and heated it to see if the solvent would evaporate and I could get back the base solid however it did not work. The sample at the moment contains the base solid, ethanol and excess water and it is cloudy, meaning that the solid is still in there. Is there any other way I could retreive the solid in the sample in order to try to recrystallize it again instead of evaporating it?

Explanation / Answer

What I understand from your decription is that you were given a solid, which is mixture of two solids, A and B. A was neutral and you have successfully separated and recrystalized it.

It is unclear if B is a base or B gets extracted with base, which means B is an acid.

Let's consider, B is a base.

B does not crystallize from ethanol, which means it is more soluble in ethanol than in water.

The sample at the moment contains B +ethanol+water.

Add excess of water to it, so that ethanol percentage becomes negligible.

Then add dichloromethane or chloroform or ether or petether to it. Shake well in separatory funnel and allow to separate in two phase.

If B is soluble in these solvents, then it will get extracted to the organic layer (bottom layer for dichloromethane and chloroform; top layer for ether and pet ether).

Collect the organic layers and evaporate solvent to get B.

Otherwise, you may try to centrifuge the mixture of B_water+ethanol to see if the cloudiness precipitates out.

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