Chlorobenzene

Structural formula
General
Surname	Chlorobenzene
other names	Monochlorobenzene; Phenyl chloride; Chlorobenzene; MCB;
Molecular formula	C 6 H 5 Cl
Brief description	colorless liquid with a benzene-like odor
External identifiers / databases
EC number	203-628-5
ECHA InfoCard	100.003.299
PubChem	7964
Wikidata	Q407768
properties
Molar mass	112.56 g mol −1
Physical state	liquid
density	1.11 g cm −3 (20 ° C)
Melting point	−45 ° C
boiling point	132 ° C
Vapor pressure	11.7 hPa (20 ° C)
solubility	very heavy in water (0.4 g l −1 at 20 ° C); good in ethanol , diethyl ether and benzene ;
Refractive index	1.5241 (20 ° C)
safety instructions
H and P phrases	H: 226-332-315-411
	P: 260-262-273-403
MAK	DFG : 10 ml m −3 or 47 mg m −3 ; Switzerland: 10 ml m −3 or 46 mg m −3 ;
Toxicological data	1110 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Chlorobenzene (C ₆ H ₅ Cl, monochlorobenzene ) is an aromatic halogenated hydrocarbon . The molecule is structured like benzene , one of the six hydrogen atoms in benzene is substituted by a chlorine atom.

presentation

Chlorobenzene is formed when benzene is chlorinated with chlorine in the presence of iron or ferric chloride. This also creates the undesirable by-product paradichlorobenzene .

properties

Physical Properties

Chlorobenzene is a colorless liquid that boils at 132 ° C under normal pressure . According to Antoine, the vapor pressure function results from log ₁₀ (P) = A− (B / (T + C)) (P in kPa, T in K) with A = 4.11083, B = 1435.675 and C = −55.124 in the temperature range from 335 K to 405 K.

Important thermodynamic quantities are given in the following table:

Compilation of the most important thermodynamic properties
property	Type	Value [unit]	Remarks
Standard enthalpy of formation	Δ _f H ⁰_liquid Δ _f H ⁰_gas	11.5 kJ mol ⁻¹ 54.42 kJ mol ⁻¹	as a liquid as a gas
Enthalpy of combustion	Δ _c H ⁰_liquid	−3112.7 kJ mol ⁻¹	as a liquid
Heat capacity	c _p	152.1 J mol ⁻¹ K ⁻¹ (25 ° C) 1.35 J g ⁻¹ K ⁻¹ (25 ° C)	as a liquid
Critical temperature	T _c	632.35K
Critical pressure	p _c	45.191 bar
Critical density	ρ _c	3.24 mol·l ⁻¹
Enthalpy of fusion	Δ _f H	9.55 kJ mol ⁻¹	at the melting point
Enthalpy of evaporation	Δ _V H	35.19 kJ mol ⁻¹	at normal pressure boiling point

Safety-related parameters

Chlorobenzene forms highly flammable vapor-air mixtures. The compound has a flash point of 28 ° C. The explosion range is between 1.3% by volume (60 g / m ³ ) as the lower explosion limit (LEL) and 11% by volume (520 g / m ³ ) as the upper explosion limit (UEL). A correlation of the lower explosion limit with the vapor pressure function results in a lower explosion point of 24 ° C. The maximum explosion pressure is 6.6 bar. The ignition temperature is 590 ° C. The substance therefore falls into temperature class T1.

use

Chlorobenzene is used as a solvent for oils, fats, resins, rubber , ethyl cellulose and phenolic resins . It also serves as a heat transfer medium and as a starting material in the production of certain silicones (phenylsiloxanes). It is an intermediate product in the manufacture of insecticides, dyes, medicines and fragrances. In the USA it is used to manufacture grinding wheels. In Germany, naphthalene is used for this purpose .

Environment and Toxicology

Like most halogenated aromatics, chlorobenzene is difficult to biodegrade. It accumulates naturally in water sediments and is absorbed by humans and animals through the drinking water. In animal tissue, it is accumulated in adipose tissue and liver. It has a paralyzing effect by attacking the nerve tissue. Damage to fetuses is possible. It is also very irritating to the skin. The fumes have a numbing effect and are nerve-damaging. The occupational exposure limit according to TRGS 900 is 10 ml · m ⁻³ or 47 mg · m ⁻³ .

The easily detectable chlorobenzene is used in environmental technology as an indicator substance for the presence of the much more toxic and difficult to detect dioxins .

New processes for the degradation of chlorobenzene in the environment use the ability of microorganisms to decompose halogenated aromatics in the presence of excess atmospheric oxygen by blowing air into polluted areas (soil, water).

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q Entry on chlorobenzene in the GESTIS substance database of the IFA , accessed on August 20, 2017(JavaScript required) .
↑ Entry on chlorobenzene. In: Römpp Online . Georg Thieme Verlag, accessed on May 22, 2014.
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-92.
↑ Entry on Chlorobenzene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 108-90-7 or chlorobenzene ), accessed on November 2, 2015.
↑ Bertram Philipp, Peter Stevens: Fundamentals of industrial chemistry. VCH Verlagsgesellschaft, Weinheim 1987, ISBN 3-527-25991-0 , p. 176.
^ I. Brown: Liquid-Vapor Equilibria. III. The Systems Benzene-n-Heptane, n-Hexane-Chlorobenzene, and Cyclohexane-Nitrobenzene. In: Aust. J. Sci. Res. Ser. A. 5, 1952, pp. 530-540.
↑ VP Kolesov, EM Tomareva, SM Skuratov, SP Alekhin: Calorimeter having a rotating bomb for determining heats of combustion of chlorinated organic compounds. In: Russ. J. Phys. Chem. (Engl. Transl.) 41, 1967, pp. 817-820.
↑ ^a ^b V. A. Platonov, Yu. N. Simulin: Determination of the standard enthalpies of formation of polychlorobenzenes. III. The standard enthalpies of formation of mono-1,2,4- and 1,3,5-tri-, and 1,2,3,4- and 1,2,3,5-tetrachlorobenzenes. In: Russ. J. Phys. Chem. (Engl. Transl.) 59, 1985, pp. 179-181.
↑ I. Shehatta: Heat capacity at constant pressure of some halogen compounds. In: Thermochim. Acta . 213, 1993, pp. 1-10. doi: 10.1016 / 0040-6031 (93) 80001-Q
^ ^A ^b ^c S. Young: The Internal Heat of Vaporization constants of thirty pure substances. In: Sci. Proc. R. Dublin Soc. 12, 1910, p. 374.
↑ Eugene S. Domalski, Elizabeth D. Hearing: Heat Capacities and Entropies of Organic Compounds in the Condensed phase. Volume III. In: J. Phys. Chem. Ref. Data. 25, 1, 1996. doi: 10.1063 / 1.555985
^ V. Majer, V. Svoboda: Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation. Blackwell Scientific Publications, Oxford 1985, p. 300.

Web links

Pollution of water sediments with chlorobenzene

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q Entry on chlorobenzene in the GESTIS substance database of the IFA , accessed on August 20, 2017(JavaScript required) .

[roempp-2] Entry on chlorobenzene. In: Römpp Online . Georg Thieme Verlag, accessed on May 22, 2014.

[CRC90_3_92-3] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-92.

[CLP_100.003.299-4] Entry on Chlorobenzene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[5] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 108-90-7 or chlorobenzene ), accessed on November 2, 2015.

[Philipp-6] Bertram Philipp, Peter Stevens: Fundamentals of industrial chemistry. VCH Verlagsgesellschaft, Weinheim 1987, ISBN 3-527-25991-0 , p. 176.

[7] I. Brown: Liquid-Vapor Equilibria. III. The Systems Benzene-n-Heptane, n-Hexane-Chlorobenzene, and Cyclohexane-Nitrobenzene. In: Aust. J. Sci. Res. Ser. A. 5, 1952, pp. 530-540.

[Kolesov-8] VP Kolesov, EM Tomareva, SM Skuratov, SP Alekhin: Calorimeter having a rotating bomb for determining heats of combustion of chlorinated organic compounds. In: Russ. J. Phys. Chem. (Engl. Transl.) 41, 1967, pp. 817-820.

[Platonov-9] V. A. Platonov, Yu. N. Simulin: Determination of the standard enthalpies of formation of polychlorobenzenes. III. The standard enthalpies of formation of mono-1,2,4- and 1,3,5-tri-, and 1,2,3,4- and 1,2,3,5-tetrachlorobenzenes. In: Russ. J. Phys. Chem. (Engl. Transl.) 59, 1985, pp. 179-181.

[Shehatta-10] I. Shehatta: Heat capacity at constant pressure of some halogen compounds. In: Thermochim. Acta . 213, 1993, pp. 1-10. doi: 10.1016 / 0040-6031 (93) 80001-Q

[Young-11] A ^b ^c S. Young: The Internal Heat of Vaporization constants of thirty pure substances. In: Sci. Proc. R. Dublin Soc. 12, 1910, p. 374.

[Domalski-12] Eugene S. Domalski, Elizabeth D. Hearing: Heat Capacities and Entropies of Organic Compounds in the Condensed phase. Volume III. In: J. Phys. Chem. Ref. Data. 25, 1, 1996. doi: 10.1063 / 1.555985

[Majer_Svoboda-13] V. Majer, V. Svoboda: Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation. Blackwell Scientific Publications, Oxford 1985, p. 300.