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The compound in question is acetanilide, and
the solvents in question are: water, ethanol, and ethyl acetate

I was thinking all three would be suitable since upon experimentation, acetanilide dissolved in all three solvents when heated.

Is it possible to rank the suitability? As, well could someone provide an explanation as to why one is more suitable than the other ?

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The ideal properties for a recrystallization solvent are that the compound of interest is soluble at high temperature but insoluble at low temperature. You have addressed the first part, so you just have to assess the second part.

Given that acetanilide is a non-polar compound, I would expect that it would have the lowest solubility in the most polar solvent. For this reason, water is probably the best, then ethanol. I would expect acetanilide to be readily soluble in ethyl acetate at room temperature, making it unsuitable for this recrystallization.

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It's not enough to be soluble. You want a solvent to have high solubility at high temperature, plus you want to have low solubility of the solute at low temperature.

Moreover, in an ideal world, you'd like the solubility of any impurities to remain higher than the target compound (i.e., they'll stay dissolved while your target crystallizes out).

So yes, it should be possible to rank the suitability, but that requires:

  • knowing the solubility at high temperature (i.e., very high)
  • knowing the solubility at low temperature (i.e., very low)
  • knowing potential impurities

The first two are absolutely necessary to rank different solvents. The third is useful, but sometimes hard to know completely.

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Acetanilide is readily soluble in ethanol at room temperature. So we can not use the ethanol as a solvent for acetanilide recrystallization. But it can soluble in water when heating. Therefore, water is the beat solvent for acetanilide.

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