1,2-Dichloroethylene

1,2-Dichloroethylene
cis-1,2-Dichloroethene (Z)	trans-1,2-Dichloroethene (E)
Names
	Preferred IUPAC name 1,2-Dichloroethene
	Other names 1,2-Dichloroethene; 1,2-DCE; Acetylene dichloride; sym-Dichloroethylene
Identifiers
CAS Number	156-59-2 (Z) ; 156-60-5 (E) ; 540-59-0 (E/Z) ;
3D model (JSmol)	Interactive image; Interactive image;
ChEBI	CHEBI:18882 ;
ChemSpider	10438 ;
ECHA InfoCard	100.007.956
EC Number	208-750-2;
KEGG	C06792 ;
PubChem CID	643833 (Z); 638186 (E); 10900 (E/Z);
UNII	FYO9G15JYD (Z) ; 41799BI61U (E) ; XU9RUA6YUT (E/Z) ;
CompTox Dashboard (EPA)	DTXSID8024991 ;
	InChI InChI=1S/C2H2Cl2/c3-1-2-4/h1-2H Key: KFUSEUYYWQURPO-UHFFFAOYSA-N ; InChI=1/C2H2Cl2/c3-1-2-4/h1-2H/b2-1- Key: KFUSEUYYWQURPO-UPHRSURJBI; InChI=1/C2H2Cl2/c3-1-2-4/h1-2H Key: KFUSEUYYWQURPO-UHFFFAOYAW;
	SMILES Cl[C@H]=CCl; ClC=CCl;
Properties
Chemical formula	C2H2Cl2
Molar mass	96.95 g/mol
Appearance	colorless liquid
Odor	sweet
Density	Z: 1.28 g/cm3; E: 1.26 g/cm3
Melting point	Z: −81.47 °C; E: −49.44 °C
Boiling point	Z: 60.2 °C; E: 48.5 °C
Magnetic susceptibility (χ)	−51.0·10−6 cm3/mol (cis); −48.9·10−6 cm3/mol (trans);
Dipole moment	Z: 1.9 D; E: 0 D
Hazards
Flash point	2–4 °C; 36–39 °F; 275–277 K
Explosive limits	5.6–12.8%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	770 mg/kg (oral, rat); 1275 mg/kg (oral, rat, trans-isomer)
LC50 (median concentration)	21,273 ppm (mouse, 6 hr, trans-isomer)
LCLo (lowest published)	16,000 ppm (rat, 6 hr, cis-isomer)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 200 ppm (790 mg/m3)
REL (Recommended)	TWA 200 ppm (790 mg/m3)
IDLH (Immediate danger)	1000 ppm
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

1,2-Dichloroethylene (1,2-DCE) is a pair of organochlorine compounds with the molecular formula C₂H₂Cl₂. The two compounds are isomers, each being colorless liquids with a sweet odor. It can exist as either of two geometric isomers, cis-1,2-dichloroethene or trans-1,2-dichloroethene, but is often used as a mixture of the two. They have modest solubility in water. These compounds have some applications as a degreasing solvent. In contrast to most cis-trans compounds, the Z isomer (cis) is more stable than the E isomer (trans) by 0.4 kcal/mol.