Respuesta :
We can recover the naphthalene from its solution at the end of the extraction by:
- All three compounds dissolve in organic solvents (such as dichloromethane or diethyl ether) better than in water. However, benzoic acid is the most acidic compound among them, it can react with bicarbonate ion.
- Phenol is less acidic than benzoic acid, but is still acidic enough to react with the hydroxide ion, which is more basic. Naphthalene is not acidic compared to these two compounds.
- Just dissolve all three compounds in an organic solvent that is not miscible with water (the two I mentioned) in a separatory funnel. First use aqueous sodium bicarbonate for extraction.
- If you use sodium hydroxide, both phenol and benzoic acid will be extracted because both can react with the hydroxide.
- If you use aqueous sodium bicarbonate, the benzoic acid will be in the aqueous layer as the benzoate ion. (Watch out for carbon dioxide gas bubbles, always release the gas after shaking.)
- Then label the first water layer. Next, do the same but use aqueous sodium hydroxide, the phenol will be extracted as phenolate. Naphthalene remains in the organic layer.
- For these two aqueous layers, add acid to protonate these anions back to their respective conjugate acid.
- These two compounds dissolve less when it is acidic. (However, phenol is still soluble in water, but substituted phenols are less soluble.) Evaporating the solvent from the organic layer yields naphthalene. If you want purer compounds, recrystallize again.
To learn more about naphthalene, refer to:
brainly.com/question/1626413
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