Solvent Extraction question at different pH levels

AI Thread Summary
The discussion focuses on the extraction of specific compounds into hexane at different pH levels. It emphasizes that the dominant form of each compound can be determined by comparing their pKa values to the pH; at lower pH, species are protonated, while at higher pH, they are deprotonated. The key point is that only neutral species can effectively extract into hexane, as charged species remain in aqueous solution. The participants confirm that the charge state of the species is critical for determining their solubility in hexane. Understanding these principles is essential for predicting solvent extraction behavior.
H98_
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The question I have been given:
Draw the dominant forms of each of the compounds below and state which, if any, would be expected to extract from aqueous solution into hexane at (a) pH 12 and (b) pH 2. CH3CH2COOH CH3CH2NH2 CH3CH2CH2OH H2NCH2CH2COOH
From my understanding, I can tell what the dominant form is by comparing the pKa of each compound to the pH; if the pH is lower, the specie is protonated. If it is higher, the specie is deprotonated. I am confused on how to tell whether it will extract into hexane? Is it based on whether the specie is charged or not (a neutral specie is the only one that will extract into hexane)?
 
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H98_ said:
Is it based on whether the specie is charged or not (a neutral specie is the only one that will extract into hexane)?

Yes.
 
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