(4) Liquid-liquid extraction(also known as solvent extraction) involves the separation of theconstituents (solutes)of a liquid solution by contact with another insoluble liquid. Solutes are separated...

(4)  Liquid-liquid extraction(also known as solvent extraction) involves the separation of theconstituents (solutes)of a liquid solution by contact with another insoluble liquid. Solutes are separated based  on  their different  solubilities  in  different  liquids.  Separation  is  achieved  when  the  substances constituting the original solution is transferred from the original solution to theother liquid solution.

(a)A solution of10per cent acetaldehyde in toluene is to be extracted with water in a five stage co-current unit. If 25 kg water/100 kg feed is used, what is the mass of acetaldehyde extracted and the final concentration? The equilibrium relation is expressed as:(kg acetaldehyde/kg water) = 2.20 (kg acetaldehyde/kg toluene)