Benzen là gì? Tính chất hóa học, công thức và ứng dụng thực tiễn

Benzene (C6H6) is known as an aromatic hydrocarbon with many applications in industry and life. Not only that, Benzene is also a commonly used organic solvent. It has a different structure from methane, ethylene or acetylene. So what is the molecular structure of benzene? What are the physical and chemical properties of benzene? Let's find out them together in today's article!

What is the concept of benzene?

Benzene is an aromatic hydrocarbon that is less soluble in water but is easily soluble in mineral oils, animal and animal oils, organic solvents, etc. Especially fat, paint, varnish, dark, rubber and asphalt, charcoal, …

In industry, benzene is a material used to synthesize many organic compounds such as anilin, chlorine benzene, nitrobenzene, phenol, … used as a solvent to dissolve fat.

Since the 1970s, Benzene has been limited in industrial use. In Vietnam, the ban on the use of benzene chemicals in industry has been specified at 108 lb/QD.

The molecular formula of benzene is: C6H6.

• Molecular mass: 78
• Molecular structure:

The general formula of benzene

Overall, benzene has a molecular formula C6H6. The general formula of benzene and its homogeneity is CnH2N-6 (n ≥ 6).

The molecular structure of benzene

Benzene is an aromatic hydrocarbon with 6 carbon atoms linked together to form a flat ring. Each carbon atom in the benzene is linked to a hydrogen atom. The bonds in the benzene ring structure are all covalent bonds. At the same time, the benzene ring has a symmetrical structure.

Benzene and homosexual

Benzene is the simplest aromatic hydrocarbon. Benzene's homosexuals are aromatic hydrocarbons that are similar to benzene but have more than 6 carbon atoms. For example: Toluen (C7H8), ethylbenzen (C8H10), Xilen (C8H10), …

How to name the name (nomenclature) is the isomorphic, isomers of Benzen

1. For the homogeneity of benzene: Call the original name ankyl + benzene.

For example:

• C6H5CH3: ethylbenzen
• C6H5CH2CH3: N-Propylbenzen
• C6H5CH (CH3) 2: Isopropylbenzen

2. Calling the isomers of benzene: Based on the position of the groups on the benzene ring, we have the prefix:

• O-: Ortho (1,2)
• M-: meta (1,3)
• P-: Para (1,4)

Example: C6H4 (CH3) 2: Xilen

• O-xilen (1,2-dimethylbenzen)
• M-Xilen (1,3-dimethylbenzen)
• P-Xilen (1.4-dimethylbenzen)

To do better homework, just knowing about the benzene structure is not enough, you need to know more about the nature of benzene from physics to chemistry.

Physical properties of benzene

Benzene (C6H6) is a colorless liquid, lighter than water and insoluble in water. Benzene can dissolve many substances such as cooking oil, rubber, candle, iodine … and many other organic solvents. Benzene is toxic and flammable.

C6H6 has a density of 0.8786 g/cm3 of liquid, melting at 5.5 degrees Celsius, boiling at 80.1 degrees C.

Chemical properties of benzene

The properties of benzene have typical chemical reactions such as fire, so and plus. C6H6 has both a reaction and a plus reaction, but the plus reaction is more difficult than C2H4 and C2H2.

Benzene flammable

Like other hydrocarbons, burning benzene in oxygen to produce CO2 and steam. However, when benzene burns in the air, in addition to CO2 and steam also produce soot.

2C6H6 + 15O2 (Temperature) → 12CO2 + 6H2O

Benzen's reaction to bromine (reaction)

Structural characteristics of benzene: When heating the benzene mixture with bromine, the iron powder is reddishly brown of the bromine and there is hido bromide gas flying out.

C6H6 (L) + Br2 (L) (T, Fe Powder) → C6H5Br (Colorless Liquid) + HBr (K)

In the above reaction, the hydrogen atom in the benzene molecule is replaced by the bromine atom.

Benzen's plus reaction

Benzene does not react with Br2 solution, proving that benzene is difficult to participate in plus reactions like C2H4 and C2H2. However, at appropriate temperature and catalyst, C6H6 participates in the reaction plus some substances, such as H2, …

C6H6 + 3H2 (T, Ni) → C6H12

How to prepare benzene?

In life, benzene is used a lot in pharmaceutical production or important substances to serve the needs of people. So how is benzene prepared? Please refer to the following use:

• Modulation of benzene from acetylene

The polymerization reaction occurs when the catalyst is C and heated at a temperature of 600 degrees C.

3CH = CH → C6H6

• Preparation of benzene from benzoic acid

C6H5COOH + NaOH → C6H6 + Na2CO3

• Preparation of benzene from charcoal distillation

• Modulation from xiclohexan uses PT and heated catalysts

C6H12 → C6H6 + 3H2

• Preparatory from N – Hexan catalyst and heat

C6H14 → C6H6 + 4H2

See also:

• What is organic compound? The concept of organic and organic chemical compounds
• What is methane? Natural state, properties, applications and modulation

Applications of benzene

In industry, benzene is used in some organic industry. Besides, they are also used to synthesize monomers in the production of polymers for plastic, rubber and fibers.

Benzene is also often used as a solvent to dissolve substances such as grease, rubber, and varnish. Used to remove grease for bones, fibers, fabrics, wool, felt, dry cleaning, grease removal for metal sheets. In addition, the tools with grease often use benzene to clean.

Benzene is also used to make substances in production such as nitrobenzene, aniline, phenol, dye synthesis, pharmaceutical, pesticide, cumene, acetone and phenol.

Is benzene poisonous? How does it affect human health?

In addition to the huge effects above, benzene is also known as a very toxic substance for their health and the ability to cause cancer is very high. People with acute benzene poisoning will experience the following symptoms:

• Headache, dizziness, nausea, confusion.

• Loss of consciousness, coma, memory loss.

• Hearing loss.

• Pneumonia.

• Burns, conjunctivitis, cornea, color blind.

• Hepatitis poisoned.

• Glomerulonephritis.

• Cardiovascular lesions

When chronic poisoning will have 2 main stages. That is:

• The onset phase causes us to have: digestive disorders, neurological disorders, hematological disorders.

• In the period of Toan Phat there will appear symptoms such as bleeding, anemia, leukemia, …

We may be poisoned by benzene through the following lines:

• In food, benzene is used to preserve food, especially bottled soft drinks.

• Benzene is in the air when we use to produce industrial at that time the gas will evaporate. Or in the waste of the means of transportation of fossil fuels.

For petroleum exploitation workers, plastic production workers, plastic production and processing workers, … To ensure health, you should see a doctor regularly, every 6 months should organize one -time examination. If detected even if only one case of poisoning is found, it is necessary to organize the examination of all exposed workers. Regarding clinical phenomena, paying attention to the body status: weight, eating, sleeping … In addition, it is necessary to detect signs of bleeding.

[FAQ] Other questions about benzene

1. Where is benzene?

Benzene is a common chemical compound in oil and coal and is also created in many industries, especially in the production of plastic, paint, dyes and detergents.

2. What is Benzene derivative?

Phenol is a typical example of benzene derivatives. It is made up when one of the hydrogen atoms in the benzene is replaced by the hydroxyl group (also known as the alcohol group, with the -OH formula).

3. What is the right benzene ring?

Despite the huge saturation, the benzene ring is very difficult to participate in the plus reaction and it is difficult to oxidize. Instead, it easily participates in the reaction (like saturated hydrocarbon).

Another remarkable point is the superior sustainability of the benzene ring. It is much more stable than the estimate from the Cyclohexatriene structure, with a difference of about 150 kJ/mol. This special stability is due to aromatic energy (aromaticity) of the benzene ring.

4. What is benzene gasoline?

Benzene is a colorless, flammable, sweet -smelled liquid and is one of the ingredients that make up the smell of gasoline. This compound is mainly used as precursors to producing more complex chemicals, such as ethylbenzen and cumen, with a year -old kilogram of global kilograms.

Exercise on Benzene SGK Chemistry 9 with solutions

Based on the above knowledge you can take advantage to solve some exercises in the 9th grade chemistry textbook:

Exercise 1 (page 125 SGK Chemistry 9)

The special structure of the benzene molecule is:

a) The molecule has 6 sides.

b) The molecule has three double bonds.

c) The molecule has 6 sides containing three double bonds alternating three single bonds.

d) The molecule has 6 sides containing three double bonds and three single bonds.

Choose the best sentence in the above sentences.

Suggestions for the answer:

Select Question c) True.

Exercise 2 (page 125 sgk)

Some students write the structural formula of benzene as follows:

Please indicate which formula is correct, wrong, why?

Suggestions for the answer:

The correct structure formula of benzene: b), d), e)

(a) Wrong because 2 pi bonds in two adjacent C atoms (wrong about the location of the double bond)

(c) wrong because there are 5 atoms C

Exercise 3 (page 125 sgk)

Let benzene act with bromine to create brombenzene:

a) Write a chemical equation (specifying the reaction conditions).

b) Calculate the mass of benzene needed to prepare 15.7g of brombenzene. Know the reaction efficiency reaches 80%.

Suggestions for the answer:

a) Reaction equation:

C6H6 + Br2 (Fe) → C6H5Br + HBr.

b) NC6H5Br = 15.7 / 157 = 0.1 mol.

According to the equation: nc6h6 = nc6h5br = 0.1 mol.

Do h = 80% should:

MC6H6 = 0.1. 78: 80% = 9.75 (g)

Exercise 4 (page 125 sgk)

Please indicate which substances in the following substances may discolor bromine solution. Explain and write chemical equations (if any).

a) C6H6.

b) CH2 = CH – CH = CH2.

c) CH3 – C.

d) CH3 – CH3.

Suggestions for the answer:

Only substance b) and c) discolor bromine solution. Because in molecules there are double bonds and bond links similar to C2H4 and C2H2.

b) CH2 = CH – CH = CH2 + 2Br2 (dd) → CH2Br – CHBr – CHBr – CH2Br.

Or: CH2 = CH – CH = CH2 + Br2 → CH2Br – CHBr – CH = CH2

c) CH3 – C ≡ CH + 2Br2 → CH3 – CBR2 – CHBr2

Or CH3 – C ≡ CH + Br2 → CH3 – CBR = CHBr

Exercise on chemical benzene for students to train themselves

Lesson 1: Which of the following is likely to participate in polymer coincidence?

A. benzene B. toluene C. 3 propane D. stiren

Lesson 2: Which of the following substances discolores KMnO4 solution at normal temperature?

A. benzene B. toluene C. propane D. stiren

Lesson 3: Benzene works with Br2 in a molar ratio of 1: 1 (Fe powder face), obtained organic products is

A.C6H6Br2 B. C6H6Br6

C. C6H5Br D. C6H6Br4

Lesson 4: Benzene works with residual H2 with a catalytic powder, obtained

A. Hex-1-en B. Hexane

C. 3 HEX-1-in D. Xiclohexan

Lesson 5: Benzene reaction with chlorine creating C6H6Cl6 occurs under:

A. There is catalytic Fe powder B. There is diffusing light

C. Water solvent D. With solvent CCl4

Lesson 6: The sequence consists of groups that make the benzene circle easier and prioritize the position M- is:

A. -CNH2N+1, -OH, -NH2 B. –CH3, -NH2, -NO2

C. –CH3, -NH2, -COOH D. –NO2, -COOH, -SO3H

Lesson 7: Which of the following reactions does not occur:

A. Benzene + Cl2 (AS) B.Benzene + H2 (Ni, Tº)

C. Benzene + Br2 (dd) D.benzen + HNO3 /H2SO4 (d)

Lesson 8: Let Benzene + Cl2 (AS) we obtain chlorine derivative A. So A is:

A.C6H5Cl BP-C6H4Cl2 C.C6H6Cl6 DM-C6H4Cl2

Lesson 9: Let benzene work with concentrated amount of HNO3 with concentrated H2SO4 catalysts to prepare nitrobenzen. What is the mass of nitrobenzen prepared from 19.5 tons of benzene (80%reaction efficiency)?

Lesson 10: substance X is the homogeneity of benzene, the simplest formula is C3H8. What is the molecular formula of X?

Lesson 11: Completely burning ankybenzen X obtained 7.84 liters of CO2 (dktc) and 3.6 grams of H2O. What is the molecular formula of X?

Above Shining Home – Gia đình Anh Ngữ has introduced you to physical properties, chemical properties, molecular structure of Benzene C6H6. Hopefully this article will help you better understand. If you need to learn more about many other subjects, you can access the website to have more interesting knowledge!

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