boiling point of trichloromethane
What is Trichloromethane?
Trichloromethane, or chloroform, is an organic compound that has been studied for decades. With its distinctive chemical composition and physical traits, it’s extensively used in both industrial and laboratory settings.
Chemical Structure and Formula
The chemical formula of trichloromethane is CHCl₃. A single carbon atom bonds with one hydrogen atom and three chlorine atoms to form a tetrahedral molecular structure. This simple yet effective composition contributes to its stability and widespread use in chemical processes.
For a deeper dive into its molecular specifics, check out this detailed breakdown of Chloroform’s structure and properties on PubChem.
Physical Characteristics
Trichloromethane has some distinct physical properties:
- Colour and Appearance: It’s a clear, colourless liquid at room temperature.
- Odour: It carries a sweet, ether-like smell that’s quite recognisable.
- Density: Trichloromethane is denser than water, sitting at approximately 1.48 g/cm³.
- Solubility: Although sparingly soluble in water, chloroform blends well with organic solvents like alcohol.
For further information, the National Pollution Inventory fact sheet gives a concise summary of its physical attributes.
Boiling Point of Trichloromethane
The boiling point of any liquid is the temperature it transitions into a gas under standard atmospheric pressure. For trichloromethane, this property not only impacts its industrial usability but also its handling and storage requirements.
The Exact Boiling Point
The boiling point of trichloromethane is 61.2°C (142.2°F) at standard atmospheric pressure (1 atm). This means that when heated to this temperature, chloroform converts from a liquid to a gaseous state. This transformation is critical in applications such as distillation processes or solvent recovery.
You can learn more about the boiling point of trichloromethane in this reference provided by the NIST WebBook.
Factors Affecting the Boiling Point
While the boiling point of chloroform under standard conditions is fixed, factors such as atmospheric pressure and purity can cause variations:
- Atmospheric Pressure: Higher altitudes with lower atmospheric pressure will reduce the boiling point, whereas increased pressure will raise it.
- Impurities in the Sample: Contaminated or impure trichloromethane may have a slightly different boiling point due to the interference of additional substances.
- Equipment and Environment: Laboratory-specific conditions, such as vacuum distillation, can alter how the compound reaches its boiling temperature.
For more comprehensive details about these factors, consult the Chloroform section on NIST WebBook.
Comparison with Similar Compounds
How does chloroform’s boiling point stack up against similar halogenated compounds? Let’s look at some comparisons:
- Dichloromethane (CH₂Cl₂): With a boiling point of 39.6°C (103.3°F), dichloromethane has a much lower boiling point due to fewer chlorine atoms in its structure.
- Tetrachloromethane (CCl₄): Also known as carbon tetrachloride, this compound has a boiling point of 76.7°C (169.1°F), higher than chloroform because of its molecular weight.
This variation in boiling points illustrates how molecular composition directly affects physical properties.
Here is a table outlining the process of trichloromethane (chloroform) synthesis
| Synthesis Method | Reaction Description |
|---|---|
| Halogenation of Methane | Reacting methane (CH₄) with chlorine (Cl₂) in the presence of heat or light to form trichloromethane (CHCl₃) and hydrogen chloride (HCl). |
| Reaction Conditions | – Chlorine is typically added in excess. – Heat or UV light is required to initiate the reaction. – The reaction is a free radical substitution mechanism. |
| Products | – Trichloromethane (CHCl₃) – Hydrogen chloride (HCl) |
| Equation | CH₄ + 3Cl₂ → CHCl₃ + 3HCl |
| Additional Notes | The reaction can be controlled to limit the formation of other chlorinated products such as tetrachloromethane (CCl₄). |
| Property | Details |
|---|
| Chemical Formula | CHCl₃ |
| Structure | Tetrahedral, one carbon atom bonded to one hydrogen and three chlorine atoms |
| Appearance | Clear, colorless liquid at room temperature |
| Odor | Sweet, ether-like smell |
| Density | 1.48 g/cm³ (denser than water) |
| Solubility | Sparingly soluble in water; highly soluble in organic solvents like alcohol |
| Boiling Point | 61.2°C (142.2°F) at standard atmospheric pressure (1 atm) |
| Factors Affecting Boiling Point | Atmospheric pressure, impurities, laboratory conditions (e.g., vacuum distillation) |
| Comparison with Similar Compounds | – Dichloromethane (CH₂Cl₂): Boiling point 39.6°C (103.3°F) – Tetrachloromethane (CCl₄): Boiling point 76.7°C (169.1°F) |
| Uses | Industrial and laboratory solvent, stability in chemical processes |
