Propylene (propene), preparation, properties, and chemical reactions.
Propylene (propene), C3H6 – organic matter class is alkenes. Propylene has a double carbon-carbon bond and therefore relates to unsaturated, or unsaturated hydrocarbon.
Propylene (propene) – organic matter class alkenes, consisting of three atoms of carbon and six atoms of hydrogen. Propylene has a double carbon-carbon bond and therefore relates to unsaturated, or unsaturated hydrocarbon.
The chemical formula of propylene is C3H6, H2CCHCH3 rational formula, structural formula CH2=CH-CH3. Isomers has not.
The structure of the molecule:
Propylene – a colorless gas, without taste, with a faint odor.
Flammable and explosive.
Poorly soluble in water. But it is well soluble in hydrocarbons.
Toxic, harmful to human – has a narcotic action is stronger than ethylene (Eten). The fourth class of danger.
|The smell||with a faint odor|
|Aggregate state (at 20 °C and atmospheric pressure of 1 ATM.)||gas|
|Density (at 20 °C and atmospheric pressure of 1 ATM.) kg/m3||1,184|
|Density (at 0 °C and atmospheric pressure of 1 ATM.) kg/m3||1,9149|
|Melting point, °C||-185,25|
|Boiling point, °C||-47,6|
|Flash point, °C||107,8|
|The auto-ignition temperature, °C||410|
|Critical temperature*, °C||91,4|
|Critical pressure, MPa||4,6|
|Explosive concentration of the mixture of gas with air, % by volume||from 2.3 to 11.1|
|Specific heat of combustion, MJ/kg||45,694|
|Molar mass, g/mol||Accounting period by 42.08|
* at temperatures above the critical temperature the gas cannot be condensed at any pressure.
Propylene — chemically active substance. Since the molecule between the atoms of carbon has a double bond, then one of them, less durable, easily broken, and in place of the connection fails accession, substitution, oxidation, polymerization of the molecules.
Chemical properties of propylene are similar to properties of other representatives of a number of alkenes. So it is characterized by the following chemical reactions:
1. catalytic hydrogenation (recovery) of propylene:
CH2=CH-CH3 + H2 → CH3-CH2-CH3 (kat = Ni, Pd, Pt, to).
As a result of this chemical reaction produces propane.
2. galogenirovannami propylene:
CH2=CH-CH3 + Br2 → CH2Br -CHBr-CH3.
3. hydrohalogenation propylene:
CH2=CH-CH3 + HBr → CH3-CHBr-CH3.
Hydrogen acid HBr joins the most gidrirovannoe the carbon atom at the double bond. Accordingly, the remainder of Br bound to a carbon atom, which is the smaller number of hydrogen atoms.
4. hydration of propylene:
CH2=CH-CH3 + H2O → CH3-of SNON-CH3 (H+, to).
The reaction occurs in the presence of mineral acids (sulphuric, phosphoric). As a result of this chemical reaction produces isopropanol (isopropyl alcohol).
5. burning of propylene:
2CH2=CH-CH3 + 9O2 → 6CO2 + 6H2O.
As a result of combustion of propylene is break all ties in the molecule, and the reaction products are carbon dioxide and water.
6. polymerization of propylene:
CH2=CH-CH3 → (-CH2-CH(CH3)-)n (kat, to).
The result is a polypropylene.
Obtaining a propylene (propene). The chemical reaction equation for the production of propylene (propene):
Propylene are produced in the laboratory and in industrial scale.
Usually propylene are produced by pyrolysis of hydrocarbons and catalytic cracking of petroleum fractions.
Industrially propylene are produced, for example, the following chemical reactions:
1. catalytic dehydrogenation of propane:
CH3-CH2-CH3 → CH2=CH-CH3 + H2 (kat = Pt, Ni, Al2O3, Cr2O3, to = 575 °C).
Propylene in the laboratory is the result of the following chemical reactions:
1. dehydration of isopropyl alcohol:
CH3-SNO-CH3 → CH2=CH-CH3 + H2O (H2SO4, H3PO4, Al2О3).
2. negalogenizirovanny dehalogenation propane:
Cl-CH2-CHCl-CH3 + Zn → CH2=CH-CH3 + ZnCl2.
Cl-CH2-CHCl-CH3 + Mg → CH2=CH-CH3 + MgCl2.
3. partial hydrogenation of propyne:
CH≡CH-CH3 + H2 → CH2=CH-CH3 (Pd, to).
4. dehydrohalogenating halogen derivatives of alkanes under the influence of alcohol solutions of alkalis:
CH3-CH2-CH2Cl + NaOH → CH2=CH-CH3 + NaCl + H2O;
– as a raw material in chemical industries for the organic synthesis of various organic compounds: propylene oxide, isopropyl alcohol, acetone, aldehydes, acrylic acid, Acrylonitrile, polypropylene,
– in the manufacture of polymers, plastics, rubbers, detergents, components of motor fuels, solvents.
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