What are the physical and chemical properties of tetrachloroethylene?
Publish Time: 2025-03-13
Tetrachloroethylene, also known as perchloroethylene, is a halogenated hydrocarbon compound widely used in industrial and commercial fields. Its chemical formula is C₂Cl₄, its molecular weight is about 165.82, and it is a colorless and transparent liquid with a sweet or pungent odor similar to chloroform. The unique physical and chemical properties of tetrachloroethylene make it play an important role in many fields.From the perspective of physical properties, tetrachloroethylene is colorless and transparent at room temperature, clear and free of impurities. Its density is about 1.62-1.63g/mL (water = 1), which is significantly higher than that of water, which means that tetrachloroethylene has a larger mass in the same volume. At the same time, the boiling point of tetrachloroethylene is 121.2℃, and the freezing point is -22.2℃ to -83.5℃ (due to different measurement conditions). This temperature range allows tetrachloroethylene to remain stable at room temperature. In addition, the vapor density of tetrachloroethylene is 5.83 times that of air, and it is easy to accumulate in low places. This characteristic requires special attention to ventilation and prevention of accumulation during use and storage.The solubility of tetrachloroethylene also has certain characteristics. It is slightly soluble in water, but can be miscible with organic solvents such as ethanol and ether. This solubility makes tetrachloroethylene widely used in fields such as organic synthesis and solvent extraction. At the same time, the vapor pressure of tetrachloroethylene is moderate, and the saturated vapor pressure is 2.11kPa at 20°C, which facilitates its use in dry cleaning and organic synthesis.In terms of chemical properties, tetrachloroethylene shows high stability. At normal temperature and pressure, it is not easy to react chemically with air or water. However, under the action of high temperature, high pressure or catalyst, tetrachloroethylene may undergo decomposition reactions to produce harmful substances such as hydrochloric acid, phosgene, carbon monoxide, etc. Therefore, when using tetrachloroethylene, special attention should be paid to avoid excessive temperatures and pressures to prevent danger.In addition, tetrachloroethylene molecules contain double bond structures, which enables it to participate in a variety of chemical reactions, such as addition reactions and substitution reactions. In addition reactions, tetrachloroethylene can react with hydrogen or halogens to produce corresponding derivatives. In substitution reactions, tetrachloroethylene can undergo hydrolysis to produce compounds such as trichloroethylene. These chemical reactions provide a broad space for the application of tetrachloroethylene in organic synthesis and chemical production.In general, the physical and chemical properties of tetrachloroethylene are unique and stable, giving it broad application prospects in dry cleaning, organic synthesis, solvent extraction and other fields. However, when using and storing tetrachloroethylene, special attention should be paid to its toxicity and flammable and explosive properties to ensure the safety of personnel and the environment. At the same time, attention should also be paid to the migration and transformation process of tetrachloroethylene in the environment to reduce its potential impact on the ecosystem.
