liquid-liquid extraction

liquid-liquuiud extraction is based on the principle that

if a substance is soluble to some extent in two immiscible liquids, most of it can be transferred from one liquid to the other by a process that involves through mixing of the liquid

the purpose of extraction in organic chemistry is to

• separate a desired organic substance from a reaction mixture or some other mixture

• to remove impurities from a desired organic substance, which is usually dissolved in an organic solvent

compounds move from one liquid to another depending on

their relative solubility in each liquid

immiscible liquids

two liquids do not dissolve well in each other

partition coefficient (K) =

molarity(solubility) in organic phase / molarity(solubility) in aqueous phase

failure to vent funnel when extracting with Na2CO3 or NaHCO3 solution can cause

the stopper to pop out

the top layer is the

lower density liquid

• typically the organic layer

the bottom layer is the

higher density liquid

• typically the aqueous layer

the two phases in extraction

aqueous and organic layer