Dichloromethane (CH2Cl2) or methylene chloride dissolves a wide range of organic compounds and is commonly used as a solvent in chemical laboratories. It can also be used in paint stripping and degreasing processes.
| IUPAC Name | Dichloromethane |
| Molecular Formula | CH2Cl2 |
| CAS Number | 75-09-2 |
| Synonyms | Methylene chloride, methylene dichloride, DCM, Narkotil, Solaesthin, Solmethine, and more |
| InChI | InChI=1S/CH2Cl2/c2-1-3/h1H2 |
Dichloromethane Density g/ml
The density of dichloromethane is 1.326 g/mL. This value indicates the mass of dichloromethane per unit volume at a given temperature and pressure. The density of dichloromethane is relatively high, making it a denser liquid than water. This property makes it useful in some laboratory applications, where it can be used to separate substances with different densities.
Dichloromethane Boiling Point
The boiling point of dichloromethane is 39.6 °C (103.3 °F). This temperature indicates the point at which the liquid form of dichloromethane will transition to its gaseous state. The low boiling point of dichloromethane makes it a highly volatile compound, which can easily vaporize at room temperature. This property makes it useful as a solvent in many laboratory applications, where it can be easily evaporated.
Dichloromethane Molar Mass
The molar mass of dichloromethane, also known as methylene chloride, is 84.93 g/mol. This value is obtained by summing the atomic masses of the atoms in a single molecule of dichloromethane. The molecular formula of dichloromethane is CH2Cl2, indicating that it contains one carbon atom, two hydrogen atoms, and two chlorine atoms. The molar mass is an important property in determining the quantity of a substance present in a given sample.
Dichloromethane Melting Point
The melting point of CH2Cl2 is -97.4 °C (-143.3 °F). This temperature indicates the point at which the solid form of CH2Cl2 will transition to its liquid state. However, CH2Cl2 is rarely found in its solid form, as it is a volatile liquid at room temperature. The low melting point of CH2Cl2 makes it difficult to freeze, and it remains a liquid even at low temperatures.
Dichloromethane Molecular Weight
The molecular weight of CH2Cl2 is 84.93 g/mol. This value is the sum of the atomic weights of the atoms in a single molecule of CH2Cl2. The molecular weight is an important property in determining the amount of a substance present in a given sample.
Dichloromethane Structure
CH2Cl2 has a tetrahedral molecular structure, with a central carbon atom bonded to two chlorine atoms and two hydrogen atoms. The molecule has a dipole moment, which arises from the difference in electronegativity between carbon and chlorine atoms. The carbon atom has a partial positive charge, while the chlorine atoms have a partial negative charge. This property makes CH2Cl2 a polar molecule.
Dichloromethane Formula
The molecular formula of dichloromethane is CH2Cl2. The formula indicates that the molecule contains one carbon atom, two hydrogen atoms, and two chlorine atoms. The formula also provides information on the relative number of atoms in a single molecule of dichloromethane. The formula is useful in determining the stoichiometry of chemical reactions involving dichloromethane.
| Appearance | Colorless liquid |
| Specific Gravity | 1.326 |
| Color | Colorless |
| Odor | Sweet, chloroform-like odor |
| Molar Mass | 84.93 g/mol |
| Density | 1.326 g/mL |
| Melting Point | -97.4 °C (-143.3 °F) |
| Boiling Point | 39.6 °C (103.3 °F) |
| Flash Point | -22 °C (-8 °F) |
| Water Solubility | 16.5 g/L at 20 °C (68 °F) |
| Solubility | Miscible with many organic solvents |
| Vapour Pressure | 44.6 kPa at 20 °C (68 °F) |
| Vapour Density | 2.93 |
| pKa | 4 |
| pH | Neutral |
Dichloromethane Safety and Hazards
Dichloromethane (CH2Cl2), also known as methylene chloride, is a hazardous chemical that poses significant safety risks if not handled properly. It is highly flammable and can cause fires or explosions if exposed to heat or open flames. Inhalation of its vapors can cause respiratory irritation, headaches, dizziness, and even unconsciousness. Skin contact with CH2Cl2 can cause irritation, burns, or chemical burns. It is also a potential carcinogen, with long-term exposure increasing the risk of liver and lung cancer. Proper safety precautions, such as using appropriate personal protective equipment and working in a well-ventilated area, are essential when working with CH2Cl2.
| Hazard Symbols | Xn, F |
| Safety Description | Highly flammable liquid and vapor. Harmful if swallowed, inhaled or absorbed through the skin. Causes skin irritation and serious eye irritation. May cause respiratory irritation. May cause drowsiness or dizziness. May be fatal if swallowed and enters airways. |
| UN Ids | UN 1593 |
| HS Code | 29031200 |
| Hazard Class | 3 |
| Packing Group | II |
| Toxicity | Dichloromethane is classified as a category 2 carcinogen and has been linked to liver and lung cancer. It is also known to cause central nervous system depression and can be fatal if ingested or inhaled in high concentrations. Proper safety precautions should always be taken when working with dichloromethane. |
Dichloromethane Synthesis Methods
There are several methods for synthesizing dichloromethane (CH2Cl2), a colorless liquid used as a solvent and paint stripper. One common method involves the reaction of methane gas with chlorine gas in the presence of a catalyst, typically aluminum chloride or ferric chloride. The reaction produces both CH2Cl2 and hydrogen chloride gas as byproducts. Another method involves the chlorination of methanol with hydrogen chloride gas or thionyl chloride. This reaction also produces CH2Cl2 as a product, along with water or sulfur dioxide as byproducts.
Another method involves the reaction of chloroform with zinc in the presence of hydrochloric acid. This reaction produces both CH2Cl2 and zinc chloride as products, with hydrogen gas as a byproduct.
The chlorination of various organic compounds, such as ethane or propane, in the presence of a catalyst can produce CH2Cl2 as a byproduct.
Regardless of the method used, it is important to handle CH2Cl2 with care due to its hazardous properties. When synthesizing and handling CH2Cl2, it is important to take proper safety precautions, such as wearing appropriate personal protective equipment and working in a well-ventilated area.
Dichloromethane Uses
Dichloromethane, which is also known as methylene chloride, finds wide application in industry and research as a versatile organic solvent. It plays a crucial role in the production of pharmaceuticals and coatings such as paints and varnishes. Moreover, it is a useful cleaning agent in the electronics manufacturing and metalworking industries for degreasing.
Dichloromethane dissolves and removes many types of paint and coatings, making it a popular paint stripper. Its use as a blowing agent in the production of polyurethane foams, polycarbonate resins, and other plastics is also noteworthy.
Apart from its industrial uses, dichloromethane is valuable in the extraction of natural products such as essential oils and fragrances from plant materials. It is also an effective solvent for many organic compounds used in laboratory reagents in organic synthesis.
However, dichloromethane requires careful handling due to its hazardous properties such as flammability and toxicity. It is important to take appropriate safety precautions, including working in a well-ventilated area and wearing appropriate personal protective equipment when working with dichloromethane.
Questions:
Q: Is dichloromethane polar?
A: Yes, dichloromethane is a polar solvent.
Q: Which of the following are hazards associated with dichloromethane?
A: Hazards associated with dichloromethane include its flammability, toxicity, and potential to cause skin and respiratory irritation.
Q: Is dichloromethane flammable?
A: Yes, dichloromethane is flammable and can cause fires or explosions if exposed to heat or open flames.
Q: Is dichloromethane soluble in water?
A: Yes, dichloromethane is slightly soluble in water. However, it is primarily used as a solvent for nonpolar compounds and is not commonly used in aqueous solutions.