Chemical equation of addition of benzene and hydrogen.

The chemical equation for the addition of benzene and hydrogen is:

C6H6+3H2→C6H 12 (cyclohexane); Nickel as catalyst

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I. Benzene

1 introduction

Benzene (C6H6), the simplest hydrocarbon, is a sweet, flammable, carcinogenic, colorless and transparent liquid with a strong aromatic smell at room temperature. It is insoluble in water, soluble in organic solvents, and can also be used as organic solvents. The ring system of benzene is called benzene ring, and the structure of benzene ring after removing a hydrogen atom is called phenyl, which is expressed by Ph, so the chemical formula of benzene can also be written as PhH. Benzene is the basic raw material of petrochemical industry, and its output and production technology level are one of the symbols of a country's petrochemical development level.

20 17,10127 October, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference, and benzene was in the list of Class I carcinogens.

2. Chemical properties

There are three kinds of chemical reactions in which benzene participates: one is the substitution reaction between other groups and hydrogen atoms on benzene ring; One is the addition reaction on benzene ring (note: benzene ring has no carbon-carbon double bond, but a unique bond between single bond and double bond); One is general combustion (oxidation reaction) (acid potassium permanganate cannot change color).

3. Physical properties

Benzene is a colorless, sweet and transparent liquid at room temperature. Its density is less than that of water, and it has a strong aromatic smell. The boiling point of benzene is 80. 1℃ and the melting point is 5.5℃. The density of benzene is lower than that of water, with a density of 0.88g/ml, but its molecular weight is heavier than that of water. Benzene is insoluble in water, and 1.7g benzene is soluble in 1 liter of water at most; However, benzene is a good organic solvent, which has strong solubility for organic molecules and some nonpolar inorganic molecules. It can be miscible with most organic solvents except polyols (such as glycerol and ethylene glycol). Inorganic substances are insoluble in benzene except iodine and sulfur. [4]

Benzene can react with water to form azeotrope with boiling point of 69.25℃ and benzene content of 9 1.2%. Therefore, benzene distillation is often added in the reaction to produce water to take it out.

Second, hydrogen.

1, Introduction:

Hydrogen [q and

Hydrogen is a highly flammable, colorless, transparent, odorless and tasteless gas at normal temperature and pressure. Hydrogen is the least dense gas known in the world, and its density is only114 of that of air, that is, at 0℃ and standard atmospheric pressure, its density is 0.0899g/L. Therefore, hydrogen can be used as the filling gas for airships and hydrogen balloons (because of its flammability and low safety, airships are now filled with helium). Hydrogen is the substance with the smallest relative molecular mass and is mainly used as a reducing agent.

Hydrogen (H2) was first produced artificially in 16 century. The method used at that time was to put the metal into strong acid. In1766–1781,hydrogen was found in Henry cavendish, and hydrogen was burned to produce water (2H2+O2 ignition =2H2O). According to this property, lavoisier named the element "hydrogenium" (meaning "substance that generates water"), and "hydro" means "water" and "gen". In 1950s, British doctor B. Hobson translated "hydrogen" into "light gas" when compiling a new collection of natural history (1855), which means the lightest gas.

At present, natural gas or water gas is generally used to produce hydrogen in industry instead of electrolyzed water with high energy consumption. The prepared hydrogen is widely used in cracking reaction and synthetic ammonia production in petrochemical industry. Hydrogen molecules can enter the crystal lattice of many metals, which leads to the phenomenon of "hydrogen embrittlement", which makes the hydrogen storage tanks and pipelines need to use special materials (such as Monel alloy) and the design is more complicated.

Hydrogen is used to treat some diseases in medicine.

2. Physical properties

Hydrogen is a colorless gas, and its density is lower than that of air. Under standard conditions, the mass of 1 liter hydrogen is 0.0899g, which is much lighter than air. Because hydrogen is insoluble in water, it can be collected by drainage and gas collection. In addition, at the pressure of 10 1 kPa and the temperature of -252.87℃, hydrogen can be converted into a light blue liquid. At -259. 1℃, it becomes a snow-like solid. At room temperature, the properties of hydrogen are very stable and it is not easy to react with other substances. But when the conditions change (such as ignition, heating, using catalyst, etc. ), the situation is different. For example, hydrogen has strong activity (especially palladium adsorption) after being adsorbed by metals such as palladium or platinum. Palladium metal has the strongest adsorption effect on hydrogen. When the volume fraction of air is 4%-75%, it may cause an explosion when it meets a fire source.

3. Chemical properties

Hydrogen is stable at room temperature and can react with many substances under the conditions of ignition or heating.

① Flammability (flammable in oxygen or chlorine): 2H2+O2= ignition =2H2O (combination reaction)

Impure hydrogen will explode if ignited, and must be purified before ignition. Similarly, deuterium (heavy hydrogen) can be ignited in oxygen to generate heavy water (D2O). )

H2+ chlorine = ignition = 2 hydrogen chloride (combination reaction)

H2+F2=2HF (hydrogen and fluorine gas mix and explode immediately to produce hydrogen fluoride gas).

② Reducibility (reduction of some metal oxides)

H2+ measures? Copper +H2O (displacement reaction)

3H2+Fe2O3= high temperature =2Fe+3H2O (displacement reaction)

3H2+WO3？ W+3H2O (displacement reaction)

reference data

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