Phenol is an important benzene intermediate, also known as carbolic acid. It is a white crystal with a low melting point (40.91℃). It turns red when placed in the air and exposed to light. It has a smell and has a boiling point of 181.84℃. Toxic to humans, care should be taken to avoid contact with skin. Industrially it is mainly produced from cumene. Phenol has a large output. In 1984, the world's total production capacity was approximately 5 megatons. Phenol has many uses. Before World War I, the only source of phenol was extracted from coal tar. Most are obtained through synthetic methods. There are methods such as sulfonation method, chlorobenzene method, and cumene method.
Phenol is mainly used in the manufacture of phenolic resin, bisphenol A and caprolactam. Among them, the production of phenolic resin is its largest use, accounting for more than half of phenol production. In addition, a considerable amount of phenol is used in the production of halogenated phenols. From monochlorophenol to pentachlorophenol, they can be used to produce 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and other herbicides; pentachlorophenol is a wood preservative; other halogenated phenol derivatives can be used as acaricides, leather preservatives and fungicides. Alkylphenols prepared from phenol are monomers for preparing alkylphenol-formaldehyde polymers, and can be used as antioxidants, nonionic surfactants, plasticizers, and petroleum product additives. Phenol is also a raw material for many medicines (such as salicylic acid, aspirin and sulfonamides, etc.), synthetic fragrances, and dyes (such as Disperse Red 3B). In addition, dilute aqueous solutions of phenol can be used directly as antiseptics and disinfectants.
Experiment on the reaction between sodium and phenol
Phenol is solid at normal temperatures and can easily react with sodium. If you use the method of heating to melt phenol and then adding metallic sodium for experiments, phenol will be easily oxidized, and the color of phenol will change during heating, which will affect the experimental results. . The steps are as follows:
Add 2 to 3 ml of anhydrous ether into a test tube, take a piece of metallic sodium the size of a soybean grain, use filter paper to absorb the kerosene on the surface, and put it into ether. You can see that the sodium does not react with the ether. Then add a small amount of phenol to the test tube and shake. At this time, you can observe that the sodium reacts rapidly in the test tube and produces a large amount of gas. The principle of this experiment is that phenol is dissolved in ether, so that the reaction between phenol and sodium can proceed smoothly.
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