Question

How does solvent extraction work?

Answer 1

Hint: The solvent extraction is done using a separating funnel where the compound is extracted from its mixture by adding the solvent in which the compounds are soluble. The solvent extraction is based on the principle of solubility.

Complete step by step answer:
The solvent extraction is the method used to separate the compound from the mixture on the basis of the solubility of the compound in the solvent.
Solvents are usually those compounds which can dissolve other compounds in it.
The solvent extraction is usually done using a separating funnel. The mixture is added in the separating funnel and solvent like ether is added with water. The mixture is shaken well so the compounds which are soluble in the solvent ether or in water dissolves completely. Most of the organic compounds are soluble in water. After shaking, put the separating funnel in a steady position and you can see that two layers are observed, the upper layer is the organic layer and the lower layer is the aqueous layer. The aqueous layers can be removed and collected separately and the organic layer is collected separately and with the help of distillation the crude compound is obtained.
During the solvent extraction process, a dynamic equilibrium is involved.
$Product(aq) \to Product(in\;ether)$
The product is distributed itself between the solvents according to the equation.
$K = \dfrac{{{C_2}}}{{{C_1}}}$
Where
K is the partition coefficient
${C_1}$ is the concentration in water
${C_2}$ is the concentration in ether

Note: Make sure that while separating the two layers, the knob present in the top of the funnel should be removed as due to shaking pressure is developed as the solvent will not move down if the knob is not removed. The ether is the upper layer because the density of ether is lower than the density of water.