When two immiscible solvents are mixed two layers form. Liquid-liquid extraction

Question

When two immiscible solvents are mixed two layers form. Liquid-liquid extractions commonly use organic solvents that are less dense than aqueous solutions and, therefore, form the top layer. An exception to this rule is chlorinated solvents which are often more dense than aqueous solution and form the bottom layer. Suppose you were unsure which layer was which during your extraction, how would you determine which layer is the aqueous layer? Suppose that just before adding a drying agent to an organic extract from an aqueous solution you notice that there is still a tiny amount of water in the organic layer. What should you do before adding the drying agent?

Explanation / Answer

a. Transferring a solute from one solvent into another is called Extraction, or liquid-liquid extraction. The solute is extracted from one solvent into the other because the solute is more soluble in the second solvent than in the first. The two solvents must be immiscible (not mix freely), and they must form two separate phases or layers, in order for the extraction to work.

b. Water must me evaporated in order to differentiate between the two layers of the imiscible layers.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.