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Q POSTLAB QUESTIONS 1. How can you improve the efficiency of an extraction proce

ID: 548097 • Letter: Q

Question

Q

POSTLAB QUESTIONS 1. How can you improve the efficiency of an extraction procedure without changing the extracting solvent to some other solvent? 2. What would happen if you first extracted the ether solution of the mixture of an organic acid and base with aqueous NaOH solution Instead of aqueous HCI? Would this make any difference in the overall results? Explain 3. 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 and which is organic?

Explanation / Answer

Organic acid and NaOH will react to form sodium salt of acid and dissolves in water. Hence In presence of NaOH organic acid will be in aqueous layer. If you extract the ether layer you will not get any compound.

When you add HCl which neutralizes NaOH and organic acid regenerates that dissolves in organic layer. If you extract the organic layer now you will get your compound.