Tetrachloroethene degradation

Tetrachloroethylene

Names
IUPAC name Tetrachloroethene
Other names Perchloroethene; Perchloroethylene; Perc; PCE
Identifiers
CAS Number	127-18-4 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:17300 N
ChEMBL	ChEMBL114062 Y
ChemSpider	13837281 Y
ECHA InfoCard	100.004.388
EC Number	204-825-9
KEGG	C06789 Y
RTECS number	KX3850000
UNII	TJ904HH8SN Y
UN number	1897
InChI InChI=1S/C2Cl4/c3-1(4)2(5)6 Y Key: CYTYCFOTNPOANT-UHFFFAOYSA-N Y InChI=1/C2Cl4/c3-1(4)2(5)6 Key: CYTYCFOTNPOANT-UHFFFAOYAO
SMILES Cl/C(Cl)=C(/Cl)Cl
Properties
Chemical formula	C2Cl4
Molar mass	165.82 g·mol−1
Appearance	Clear, colorless liquid
Odor	mild, chloroform-like
Density	1.622 g/cm3
Melting point	−19 °C (−2 °F; 254 K)
Boiling point	121.1 °C (250.0 °F; 394.2 K)
Solubility in water	0.15 g/L (25 °C)
Vapor pressure	14 mmHg (20°C)
Magnetic susceptibility (χ)	-81.6·10−6 cm3/mol
Viscosity	0.89 cP at 25 °C
Hazards
Main hazards	Harmful (Xn), Dangerous for the environment (N)
Safety data sheet	See: data page External MSDS
R-phrases (outdated)	R40 R51/53
S-phrases (outdated)	S23 S36/37 S61
NFPA 704	0 2 0
Flash point	Not flammable
Lethal dose or concentration (LD, LC):
LC50 (median concentration)	4000 ppm (rat, 4 hr) 5200 ppm (mouse, 4 hr) 4964 ppm (rat, 8 hr)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 100 ppm C 200 ppm (for 5 minutes in any 3-hour period), with a maximum peak of 300 ppm
REL (Recommended)	Ca Minimize workplace exposure concentrations.
IDLH (Immediate danger)	Ca [150 ppm]
Related compounds
Related Related organohalides	Tetrabromoethylene Tetraiodoethylene
Related compounds	Trichloroethylene Dichloroethene Tetrachloroethane
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Tetrachloroethylene, also known under the systematic name tetrachloroethene, or perchloroethylene ("perc" or "PERC"), and many other names, is a chlorocarbon with the formula Cl₂C=CCl₂. It is a colorless liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid". It has a sweet odor detectable by most people at a concentration of 1 part per million (1 ppm). Worldwide production was about 1 million metric tons (980,000 long tons; 1,100,000 short tons) in 1985.

Michael Faraday first synthesized tetrachloroethylene in 1821 by thermal decomposition of hexachloroethane.

Most tetrachloroethylene is produced by high temperature chlorinolysis of light hydrocarbons. The method is related to Faraday's discovery since hexachloroethane is generated and thermally decomposes. Side products include carbon tetrachloride, hydrogen chloride, and hexachlorobutadiene.

Several other methods have been developed. When 1,2-dichloroethane is heated to 400 °C with chlorine, tetrachloroethylene is produced by the chemical reaction:

This reaction can be catalyzed by a mixture of potassium chloride and aluminium chloride or by activated carbon. Trichloroethylene is a major byproduct, which is separated by distillation.

According to a United States Environmental Protection Agency (EPA) report of 1976, the quantity of tetrachloroethylene produced in the United States in 1973 totaled 320,000 metric tons (706 million lb). By 1993, the volume produced in the United States had dropped to 123,000 metric tons (271 million lb).