Brominerain
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multiple solvent recrystallization
I know how conventional recrystallization works. (dissolving a substance in hot solvent and then cooling the solution slowly to lower the solubility
to form crystals)(correct me if needed).
However, I am curious to know how multiple solvent recrystallization works. Is it a viable technic of purification?
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DraconicAcid
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Yes, very much so.
In a mixed solvent recrystallization, you have a solvent (which dissolves the solute well) and an antisolvent (which doesn't). You can dissolve your
substance in solvent, and then slowly add AS until your solute crystallizes out. Ifg you want really nice crystals, you can put a small beaker of
solute dissolved in S into a jar of a volatile AS, so that AS vapour slowly diffuses into the solution.
You can also suspend your solid in hot AS, add just enough S to dissolve your solute, and then cool slowly.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Herr Haber
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Good video on the subject:
https://youtu.be/VwzwYahkJEs
The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
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Mateo_swe
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In ordinary crystallization you dissolve a substance in a minimal amount of hot solvent so it just dissolves the substance and then cooling the
solution slowly to lower the solubility to form crystals. The slower the temperature drops, the nicer and larger crystals are formed.
Putting it in your dedicated chemistry refrigerator to cool down usually works if you don't need very large nice crystals.
Sometimes scratching the inside of the beaker with a glass rod or using a seed crystal is needed to initiate the crystallization.
Using a minimal of solvent that are able to dissolve the compound is good, its not always that important but some compounds are harder to get to
crystallize so its a good way to get better results.
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