how to separate a mixture of benzoic acid,phenol,aniline,and naphthalene?
- 10 years agoFavourite answer
Dissolve the (pressumably solid) mixture in an organic solvent, (diethylether, or hexane.. or similar.)
Then, in a seperating funnel, add an (Aqueous) solution of sodium hydroxide. The Phenol, and benzoic acid, as acids, will react with the base to form phenolate and benzenoate ions, which will dissolve into the water layer. Collect this layer, and re-precipitate the organic molecules by adding concentrated Hydrochloric acid. The phenol and Benzoic acid can be seperated via their varying solubilities, (8.3g/100ml vs 0.34g/100ml. respectively) by heating the mixture in water to dissolve the phenol, and then filtering of the (practically) insoluble benzoic acid. The solution can then be acidified (with HCl) to return the phenol.
Now add a solution of hydrochloric acid to the seperating funnel, which (as before) will react with the basic anniline dossilving it into the water. Collect the aqueous layer and re-precipitate the anniline with excess sodium hydroxide.
finally boil off the remaining organic solvent to obtain the napthalene, which was left untouched by all the acids and bases.
- JudithLv 44 years ago
Benzoic acid sol in water 2.7 g/L naphthalene sol in water 30 mg/L