Tetrachloroethylene (C2Cl4) is a colorless, nonflammable liquid commonly used in dry cleaning. It can cause health issues such as dizziness, headaches, and liver damage if ingested or inhaled excessively.
| IUPAC Name | Tetrachloroethene |
| Molecular Formula | C2Cl4 |
| CAS Number | 127-18-4 |
| Synonyms | Perchloroethylene, PCE, Tetrachloroethene, Carbon tetrachloride dimer, 1,1,2,2-Tetrachloroethylene |
| InChI | InChI=1S/C2Cl4/c3-1(4)2(5)6 |
Tetrachloroethylene Properties
Tetrachloroethylene Formula
Tetrachloroethylene, also known as perchloroethylene or PCE, has a chemical formula of C2Cl4. This means that each molecule of tetrachloroethylene is composed of two carbon atoms and four chlorine atoms. The formula is important because it helps us understand the molecular structure and properties of tetrachloroethylene.
Tetrachloroethylene Molar Mass
The molar mass of C2Cl4 is 165.83 g/mol. This means that one mole of C2Cl4, which is equal to 6.022 x 10^23 molecules, weighs 165.83 grams. The molar mass is important in chemical calculations and can help in determining the amount of C2Cl4 needed for a specific reaction.
Tetrachloroethylene Boiling Point
The boiling point of C2Cl4 is 121.1°C (250°F). This means that at a temperature of 121.1°C, C2Cl4 will transition from a liquid to a gas. The boiling point is an important property because it affects the way C2Cl4 behaves in different environments.
Tetrachloroethylene Melting Point
The melting point of C2Cl4 is -22.94°C (-9.31°F). This means that at a temperature below -22.94°C, C2Cl4 will transition from a solid to a liquid. The melting point is important in determining the physical state of C2Cl4 at different temperatures.
Tetrachloroethylene Density g/mL
The density of C2Cl4 is 1.62 g/mL at room temperature. This means that C2Cl4 is denser than water, which has a density of 1 g/mL. The density is important in understanding the physical properties of C2Cl4 and its behavior in different environments.
Tetrachloroethylene Molecular Weight
The molecular weight of C2Cl4 is 165.83 g/mol. This means that the weight of one molecule of C2Cl4 is 165.83 atomic mass units. Molecular weight is important in chemical calculations and can help in determining the amount of C2Cl4 needed for a specific reaction.
Tetrachloroethylene Structure
The structure of C2Cl4 consists of two carbon atoms and four chlorine atoms arranged in a tetrahedral shape. The carbon atoms are connected by a double bond, while each chlorine atom is bonded to one of the carbon atoms. The structure is important in understanding the chemical and physical properties of C2Cl4.
Tetrachloroethylene Solubility
C2Cl4 is insoluble in water, but it is soluble in organic solvents such as alcohol and ether. This means that C2Cl4 will not dissolve in water, but it can dissolve in other substances. The solubility is important in understanding the behavior of C2Cl4 in different environments, such as in industrial or laboratory settings.
| Appearance | Colorless liquid |
| Specific Gravity | 1.62 at 20°C |
| Color | Colorless |
| Odor | Sweet, ether-like odor |
| Molar Mass | 165.83 g/mol |
| Density | 1.62 g/mL at 20°C |
| Melting Point | -22.94°C |
| Boiling Point | 121.1°C |
| Flash Point | 55°C |
| Water Solubility | 0.015 g/100 mL at 25°C |
| Solubility | Soluble in alcohol and ether |
| Vapour Pressure | 10 mmHg at 20°C |
| Vapour Density | 5.7 |
| pKa | 1.8 |
| pH | Not applicable (pure substance) |
Tetrachloroethylene Safety and Hazards
C2Cl4 can be harmful if inhaled, ingested, or comes into contact with the skin or eyes. It may cause dizziness, headaches, confusion, and respiratory irritation. Long-term exposure can lead to liver and kidney damage and may increase the risk of certain cancers. It is important to handle C2Cl4 with care and use proper protective equipment when working with it. The substance should be stored in a well-ventilated area and kept away from sources of heat or ignition. Spills should be immediately cleaned up and disposed of properly in accordance with local regulations.
| Hazard Symbols | Skull and crossbones, Flame |
| Safety Description | Highly flammable, Toxic if inhaled or swallowed, May cause cancer, May cause damage to organs |
| UN ID | UN 1897 |
| HS Code | 290323 |
| Hazard Class | 6.1 (Toxic substances) |
| Packing Group | III |
| Toxicity | Tetrachloroethylene is classified as a Group 2A carcinogen (probably carcinogenic to humans) by the International Agency for Research on Cancer (IARC) and as a Category 2 reproductive toxin by the European Union. |
Tetrachloroethylene Synthesis Methods
To synthesize C2Cl4, one can use various methods, such as directly chlorinating ethylene, chlorinating ethylene dichloride, or chlorinating carbon tetrachloride.
Ethylene gas reacts with chlorine gas in a reactor to form C2Cl4 during the direct chlorination method. This method can produce high yields of C2Cl4 but requires careful control of reaction conditions to avoid unwanted byproducts.
The second method involves the chlorination of ethylene dichloride, which is a byproduct of vinyl chloride production. This method also produces high yields of C2Cl4 but can result in the formation of toxic byproducts such as hexachlorobutadiene.
The third method involves the chlorination of carbon tetrachloride, which can yield C2Cl4 as a byproduct. However, this method is less efficient and produces lower yields than the other two methods.
Apart from these methods, it is also possible to produce C2Cl4 by reacting trichloroethylene with chlorine gas or by reacting hexachloroethane with phosgene.
On an industrial scale, manufacturers commonly use the direct chlorination of ethylene and the chlorination of ethylene dichloride as the most commonly used methods for producing C2Cl4.
Tetrachloroethylene Uses
C2Cl4 has several industrial and commercial uses, including:
- Dry cleaning: Widely used as a solvent for dry cleaning clothes due to its ability to dissolve a wide range of stains and soils.
- Metal degreasing: An effective solvent for removing oil and grease from metal surfaces, making it useful in the metalworking industry.
- Adhesives and sealants: Used as a solvent in the manufacture of adhesives and sealants, as it can dissolve many types of polymers and resins.
- Chemical intermediates: Used as a starting material in the production of other chemicals, such as chlorinated solvents and fluorocarbons.
- Textile and leather processing: Used in textile and leather processing as a solvent and to remove impurities.
- Refrigerant: Some applications use C2Cl4 as a refrigerant, but environmental concerns are phasing out this use.
- Laboratory solvent: Also used as a solvent in laboratory settings, particularly for chromatography and spectroscopy applications.
Questions:
Q: What is tetrachloroethylene?
A: C2Cl4, also known as perchloroethylene or PCE, is a colorless liquid with a sweet odor that is widely used as a solvent in various industrial and commercial applications.
Q: Will tetrachloroethylene float on water?
A: No, C2Cl4 is denser than water, so it will sink and form a separate layer on the bottom.
Q: Where to buy dry cleaning solvent tetrachloroethylene (perchloroethylene)?
A: C2Cl4 is a regulated substance and can only be purchased by licensed professionals in the dry-cleaning industry. It is typically purchased from chemical suppliers or distributors that specialize in industrial solvents.
Q: How is tetrachloroethylene related to carbon tetrachloride?
A: C2Cl4 and carbon tetrachloride are both halogenated hydrocarbons that contain chlorine atoms, but they have different molecular structures and properties. Carbon tetrachloride is a nonpolar molecule, whereas C2Cl4 is polar due to the presence of a double bond between two carbon atoms.
Q: Tetrachloroethylene in water?
A: C2Cl4 is only slightly soluble in water and tends to partition into soil and sediment, making it a common groundwater and soil contaminant.
Q: Tetrachloroethylene testing companies?
A: There are many environmental testing companies that offer C2Cl4 testing services for water, soil, and air samples. Some examples include ALS Global, Eurofins TestAmerica, and Environmental Testing and Consulting, Inc.
Q: What is the hybridization of the C atoms in C2Cl4?
A: The C atoms in C2Cl4 have sp2 hybridization, meaning that they have three hybrid orbitals that are involved in bonding with other atoms.
Q: What is the approximate chlorine-carbon-chlorine bond angle in C2Cl4?
A: The approximate chlorine-carbon-chlorine bond angle in C2Cl4 is 120 degrees, which is characteristic of molecules with a trigonal planar geometry.
Q: Is C2Cl4 polar or nonpolar?
A: C2Cl4 is a polar molecule due to the presence of a double bond between the carbon atoms, which results in an asymmetrical distribution of charge and a dipole moment.