Pre–lab questions:
1. What is the primary hazard associated with the use of diethyl ether?
2. Why are carboxylic acids, even large ones, soluble in aqueous base?
3. Why do we “vent” separatory funnels?
4. A student tried to extract a compound from water using ethanol. It didn’t work. Why not?
5. If you have an aqueous and an organic layer in a separatory funnel, how could you
easily determine which is which? (Assume that you don’t know the densities.)
6. Partition coefficients describe how a solute is distributed between two immiscible
solvents. They are used in drug design as a measure of a solute’s hydrophobicity and a proxy for its membrane permeability. If morphine has a partition coeffiecent, K, of 2 in petroleum ether and water, and a water solubility of 1.0 g/17.6 mL, what is the solubility of morphine in petroleum ether?
7. Solute A has a partition coefficient of 1.0 between water and diethyl ether. If a
solution which is 0.20 g of A per 4.0 mL of a water solution is extracted with one 2.0 mL
portion of ether, how much A would remain in the water?
If the same starting solution is extracted with 1.0 mL of ether TWO times, how much
A would remain in the water after the second extractio
