WOLFRAM|DEMONSTRATIONS PROJECT

Separatory Funnel Extraction

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initial mass of compound (grams)
1
volume of phase 1 (mL)
1
volume of phase 2 (mL)
1
number of extractions n
1
2
3
4
5
6
7
8
9
10
partition coefficient (Kp)
1
comparison
line graph
quantitative
bar graph
equation for mass extracted:
inital mass-initial mass ×
number of extractions
volume phase 1
(partition coefficient × volume phase 2) + volume phase 1
extractions
mass extracted
mass remaining
volume of phase 2 used
1
0.5
0.5
1
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A separatory funnel is often used to remove a compound from a mixture (called phase 1) by mixing it with a different solvent (called phase 2) that is immiscible (will not mix) with phase 1. The partition coefficient of the compound is the solubility of the compound in phase 2 divided by the solubility of the compound in phase 1. Thus a phase 2 that has the greatest partition coefficient will be chosen to extract the compound. The best way to extract a compound from a mixture is to use either a phase 2 for which the compound is very soluble (seen by increasing the partition coefficient) or a greater volume of phase 2 compared to phase 1.
A large number of extractions with smaller volumes is more efficient then a single extraction with a large phase 2 volume, as you can see in the bar graph tab as the number of extractions is increased.