Question

according to figure 2, which compound would be extracted if we treat our mixture with hcl, separate the layers and treat the aqueous layer with sodium hydroxide
askcuddy
correct answer:
the answer is benzoic acid.
explanation:
benzoic acid
benzocaine
naphthalene and benzoic acid
phenol
naphthalene

Explanation:

When the mixture is treated with HCl, basic compounds (like benzocaine) react with HCl to form salts and enter the aqueous layer. Then, when the aqueous layer is treated with sodium hydroxide, acidic compounds (like benzoic acid) which can react with the base to be "re - extracted" (in a sense of changing its solubility properties again). Phenol has a weaker acidity compared to benzoic acid in this context (lower \(pK_a\) for benzoic acid makes it more reactive with the base in the second step). Naphthalene is non - polar and would not be in the aqueous layer after HCl treatment.

Answer:

A. benzoic acid