Answer:
Avoid emulsion by salting-out effect
Explanations:
What is an extraction?
Extraction is a separation process which deals with the separation of a substance from a matrix.
Sodium chloride (NaCl) is important during the extraction process. The addition of salt to the aqueous layer during extraction increases the surface tension of the droplets thereby causing an increase in density of the aqueous layer which in turn forces a separation.
If water is being used as a solvent during the extraction process, the addition of saturated NaCl helps to destroy the emulsion effect. Due to the salting-out effect, NaCl increases the polarity of the water molecules thereby facilitating the separation from other solutes in a solute-solvent system.
Based on the explanation above, we can conclude that the role of adding NaCl to the aqueous layer while performing extraction is to avoid emulsion by salting out effect.