Inthis experiment, an acid-base extraction was performed for the purpose ofseparating a mixture of benzoic acid, 4-chloroaniline, and naphthalene. Aftereach has been isolated, a melting point apparatus was utilized to measure themelting point of each compound. Extraction is a fundamental type of techniqueexperiment.
The most critical of extractions applied in Organic Chemistry aresolid-liquid, liquid-liquid, and acid-base extractions. In a solid-liquidextraction, a solid compound is dissolved into a liquid permissible for thatsubstance, and then is removed through a filtration process. The primitive goalbehind the concept of a liquid-liquid extraction is to resolve a solution withan unequal dispersion of a solute between two immiscible solvents. 1 Thisparticular experiment is composed of an acid-base extraction, in which thereare subsequent liquid-liquid extractions in attempt to isolate acids and basesfrom a mixed solution using knowledge of their chemical properties.
Solventsystems for extraction experiments must follow a few guidelines to ensure successfulresults. Solvents must freely dissolve the extraction substance, should not reactwith this substance, should not be able to combine with the water, and should havea relatively low boiling point to make it easy to remove. Duringthis acid-base extraction, the first to be isolated from the mixture in the separatoryfunnel was the 4-chloroaniline, followed by the benzoic acid, and then finally thenaphthalene.
To extract the 4-chloroaniline, a base, was combined with an aqueousacid to form a salt, which was then treated with a strong ionic base, NaOH, in orderto regenerate. Similarly, benzoic acid, an organic acid was united with NaOH, itscontrary, to form a salt and then again with HCl, a strong organic acid to uncoverthe acidity in the solution. The aqueous layer was then disposed of, with the neutralcompound, naphthalene, left to be evaporated from the organic layer.