Does decreasing pH decrease solubility of adipic acid?

I added 3 grams of adipic acid to 150ml deionized water with heating + mixing until it was completely dissolved. This was then boiled and cooled to allow crystals to form. The maximum amount of adipic acid recovered was 2.62g. Is there a way to recover more of the acid *without* completely boiling off the solution? Does decreasing the pH decrease the solubility of adipic acid?




Yes it will. Protonated [adipic acid](https://en.m.wikipedia.org/wiki/Adipic_acid) is less soluble in water than sodium adipate. Colder temperatures also make it less soluble.


It can be extracted into a non-polar solvent that is more easily evaporated. Drying under excessive heat may degrade adipic acid. Vacuum may be better.


Some adipic acid will remain in solution if water is still present, but with multiple batches, losses can be reduced by using the same "mother liquor".


Try putting your re-crystallization solution in the refrigerator.


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