Laboratory separation method of toluene, aniline, phenol and benzoic acid_Kain Industrial Additive

Methods for separating toluene, aniline, phenol and benzoic acid

First pass the mixture into NaHCO3 solution to separate benzoic acid. Then pass the NaOH solution to separate the phenol. By adding hydrochloric acid, aniline can be separated. Finally, toluene remains.

1. Add NaHCO3 solution, benzoic acid enters the water phase, and toluene, aniline, and phenol are in the organic phase. Separate to obtain sodium benzoate. Add some HCl and separate to obtain benzoic acid.
2. Add NaOH solution, phenol enters the water phase, aniline and toluene are in the organic phase, and the liquid is separated to obtain sodium phenolate. Add some HCl and then separate the liquid to obtain phenol.
3. Add HCl solution, and aniline will become an ammonium salt soluble in water. Toluene is in the organic phase. After separation, add NaOH solution and aniline will be free again, and you will be successful.

The solubility of aniline and phenol in water is greater than that in nitrobenzene

What are the alkaline strengths of the three compounds aniline, acetanilide and N-methylaniline?

Aniline is the weakest alkaline. The electrons on the nitrogen are conjugated to the benzene ring. The electron density is reduced and the ability to absorb protons is weakened, so it is less alkaline. Then there is N-methylbenzene, which has one more methyl group than aniline. The methyl group is an electron-donating group, making the electron density on the nitrogen higher than that of aniline and making it more basic. By the same principle, acetanilide is the most basic.