Is benzene board poisonous?

The simplest aromatic hydrocarbon. The molecular formula is C6H6. It is one of the basic raw materials of organic chemical industry. Colorless, flammable and odorous liquid. The melting point is 5.5℃, the boiling point is 80.65438 0℃, and the relative density is 0.8765 (20/4℃). Almost insoluble in water, it can be mixed with organic solvents such as ethanol, ether and carbon disulfide. It can form an azeotropic mixture with water, with a boiling point of 69.25℃ and a benzene content of 9 1.2%. Therefore, benzene distillation is often added in the reaction of generating water to take it out. When benzene burns, it produces thick smoke.

Benzene can undergo substitution, addition and oxidation reactions. Benzene is nitrated with a mixture of nitric acid and sulfuric acid to produce nitrobenzene, and nitrobenzene is reduced to produce aniline, which is an important dye intermediate. Benzene is sulfonated with sulfuric acid to produce benzene sulfonic acid, which can be used to synthesize phenol; Benzene reacts with chlorine in the presence of ferric chloride to produce chlorobenzene, which is an important intermediate. Benzene reacts with ethylene, propylene or long-chain olefins in the presence of anhydrous aluminum trichloride and other catalysts to produce ethylbenzene, cumene or alkylbenzene. Ethylbenzene is the raw material for synthesizing styrene, cumene is the raw material for synthesizing phenol and acetone, and alkylbenzene is the raw material for synthesizing detergent. Catalytic hydrogenation of benzene to cyclohexane is the raw material for synthesizing nylon. Insecticide 666 can be obtained by adding three molecules of chlorine to benzene under illumination. Because it is toxic to people and animals, its production and use have been banned. Benzene is difficult to be oxidized, but in the presence of vanadium oxide, it can be oxidized to maleic anhydride at 450℃, which is the raw material for synthesizing unsaturated polyester resin. Benzene is a good solvent for rubber, fat and many resins, but it has been gradually replaced by other solvents because of its high toxicity. Benzene can be added to gasoline to improve its antiknock performance. Benzene is produced industrially by catalytic reforming of naphtha fraction from petroleum refining, or recovered from coking coke oven gas. Benzene vapor is toxic, which can cause convulsion and even unconsciousness when acute poisoning is serious; Chronic poisoning can damage hematopoietic function.

In 1865, F.A. Kekule proposed the cyclic structural formula of benzene, which is still in use today. According to the description of quantum chemistry, as a whole, six π electrons in benzene molecule are distributed above and below the torus. Therefore, in recent years, the structure of benzene is also expressed by the formula +0b in Figure 65438.

Benzene is a colorless liquid with a special aromatic smell. It is miscible with alcohol, ether, acetone and carbon tetrachloride and slightly soluble in water. Benzene is volatile and flammable, and its vapor is explosive. Frequent exposure to benzene can make the skin dry and desquamate due to degreasing, and allergic eczema appears in some cases. Long-term inhalation of benzene can cause aplastic anemia.

Benzene molecules have a planar regular hexagonal structure. Each bond angle is 120, and the bond length between carbons on the hexagonal ring is1.40×10-10 m. It is different from ordinary single bonds (the bond length of C-C bond is1.54×10-10 m) and ordinary double bonds (the bond length of C=C bond is1.33×10-/kloc-0). From the fact that benzene can not react with potassium permanganate solution and bromine water and the experimental data of carbon-carbon bond length, it is fully explained that the carbon-carbon bond on benzene ring should be the only bond between single bond and double bond.