Is Naphthalene soluble in water, NaOH, HCL and/or Diethyl ether? and why?
The correct answer and explanation is:
Naphthalene is not soluble in water, soluble in NaOH (to some extent), insoluble in HCl, and soluble in diethyl ether. Below is the explanation for each solvent:
- Water: Naphthalene is insoluble in water because it is a nonpolar compound, while water is a highly polar solvent. The principle of solubility follows the rule “like dissolves like,” meaning polar substances generally dissolve in polar solvents, and nonpolar substances dissolve in nonpolar solvents. Since naphthalene is nonpolar, it does not interact effectively with the polar water molecules, making it insoluble.
- NaOH (Sodium Hydroxide): Naphthalene is slightly soluble in NaOH due to the weakly acidic nature of the naphthalene’s aromatic ring. NaOH can deprotonate the naphthalene, especially in the presence of high concentration. However, this interaction is weak, and solubility is limited. Naphthalene does not readily form a stable salt with NaOH, so its solubility in NaOH is not as high as in some other solvents.
- HCl (Hydrochloric Acid): Naphthalene is insoluble in HCl because it does not form any stable ionic compounds with hydrochloric acid. Naphthalene’s nonpolar nature and lack of a functional group that reacts with acids make it difficult to dissolve in hydrochloric acid, which is a strong acid.
- Diethyl Ether: Naphthalene is soluble in diethyl ether because diethyl ether is a nonpolar organic solvent, like naphthalene. Since they share similar polarity (both are nonpolar), they are able to interact more easily, resulting in naphthalene dissolving in diethyl ether. The solubility in diethyl ether is high, making it an effective solvent for extracting naphthalene.
Thus, the solubility behavior of naphthalene depends heavily on the polarity of the solvent involved.