How Is Chloroform Used and Why Is It Important?
Chloroform is an important chemical compound in organic chemistry, recognized by its formula CHCl3. This colorless, volatile liquid was once widely used as an anesthetic but is now primarily found as an industrial solvent and as a byproduct of water chlorination. Understanding chloroform meaning, its effects, structure, uses, and hazards is essential for students and professionals in chemistry and environmental sciences.
What is Chloroform? (Structure and Properties)
Chloroform, also referred to as trichloromethane, is a chlorinated hydrocarbon and an example of a haloalkane.
Chemical Structure and Formula
- Chemical formula: \( CHCl_3 \)
- Chloroform structure: One carbon atom bonded to one hydrogen and three chlorine atoms (tetrahedral geometry)
Physical Properties
- Appearance: Clear, colorless, volatile liquid
- Characteristic sweet odor
- Chloroform boiling point: 61.2°C
- Density: 1.48 g/cm3
- Low water solubility (~0.8 g/L at 25°C)
Learn more about boiling point concepts and how different intermolecular forces affect it.
Chloroform in Water and Environment
- Common trace contaminant in chlorinated drinking water and swimming pools
- No significant natural sources; forms mainly during water disinfection
- Chloroform in well water possible near industrial or wastewater sites
Explore the causes of water pollution for a broader understanding of such contaminants.
Chloroform Uses in Industry and Research
While no longer used as a medical anesthetic due to its toxicity, chloroform remains crucial in various applications:
- Solvent for fats, alkaloids, and rubber
- Intermediate in the manufacture of refrigerants like Freon
- In laboratory protocols (e.g., DNA extraction using phenol-chloroform)
- Tissue processing in histology
See how other solvents are used in chemistry by visiting real-world examples of solvents.
Chloroform Effects and Hazards
Awareness of chloroform side effects and safety guidelines is critical due to its high toxicity and environmental persistence:
- Short-term exposure (inhalation or ingestion) can cause dizziness, fatigue, headache, and loss of consciousness
- High doses damage the liver and kidneys
- Chronic exposure linked to cancer and reproductive harm
- Decomposition in sunlight produces phosgene (COCl2), a toxic gas
Understand more about the impact of chemicals on the environment and proper handling measures.
Chloroform Safety Data Sheet (SDS) Highlights
- Store in a cool, dry, well-ventilated area away from light
- Use safety goggles and gloves; always work in a fume hood
- Avoid inhalation, ingestion, and prolonged skin contact
Key Summary Table: Chloroform Basics
| Chemical Formula | CHCl3 |
| Density | 1.48 g/cm3 |
| Boiling Point | 61.2°C |
| Major Uses | Solvent, refrigerant production, lab extraction |
| Hazards | Toxic, possible carcinogen, environmental contaminant |
For more about basic chemical principles, check types of chemical compounds and their properties.
Chloroform plays a complex role in chemistry and daily life as a solvent and environment pollutant. Its unique properties—including low boiling point, distinct density, and tetrahedral structure—make it useful in industry, but also demand careful handling due to harmful effects. Awareness of chloroform SDS, side effects, and environmental impact is crucial for safe usage and disposal. Always use rigorous safety measures and stay informed about this important compound.
FAQs on What Is Chloroform? Properties, Uses, and Safety
1. What is chloroform?
Chloroform is a clear, colorless, and sweet-smelling liquid compound with the chemical formula CHCl₃. It is commonly used as a solvent and was once used as an anesthetic.
- Belongs to the group of trihalomethanes.
- Non-flammable and heavier than air.
- Now mainly used in industry and laboratories.
2. How is chloroform prepared in the laboratory?
Chloroform can be prepared in the laboratory by the reaction of ethanol or acetone with bleaching powder (Ca(OCl)₂).
- Mix ethanol or acetone with bleaching powder and water.
- Chloroform forms by oxidation and hydrolysis.
- Chemical reactions involve: CH₃CH₂OH + 4Cl₂ → CCl₃CHO + 5HCl and then, CCl₃CHO + Ca(OH)₂ → CHCl₃ + HCOONa.
3. State two uses of chloroform.
Chloroform is mainly used as an industrial solvent and in chemical manufacturing.
- Used as a solvent for fats, alkaloids, and rubber.
- Important in the production of refrigerant (Freon) and other organic compounds.
4. What are the harmful effects of chloroform?
Exposure to chloroform can cause several health hazards, making it a dangerous chemical.
- High concentrations may cause dizziness, unconsciousness, and organ damage.
- Long-term exposure can damage the liver, kidneys, and nervous system.
- It is considered a possible carcinogen (may cause cancer).
5. What happens when chloroform is exposed to air and sunlight?
When exposed to air and sunlight, chloroform decomposes to form toxic phosgene gas (COCl₂).
- This reaction is accelerated by the presence of oxygen and light.
- Phosgene gas is highly poisonous.
- To prevent this, chloroform is stored in dark, airtight bottles with a little ethanol (acts as a stabilizer).
6. Why is chloroform no longer used as an anesthetic?
Chloroform is no longer used as an anesthetic because of its severe toxic effects on the liver and heart.
- Safer alternatives are now available.
- It could cause irregular heartbeat, liver damage, and sometimes death.
- It is recognized by medical authorities as too risky for anesthesia.
7. Name the chemical formula and IUPAC name for chloroform.
Chloroform's chemical formula is CHCl₃ and its IUPAC name is trichloromethane.
8. How is chloroform stored safely?
Chloroform should be stored in tightly closed, dark bottles, preferably with a little ethanol as a stabilizer, to prevent the formation of phosgene on exposure to air and light.
9. Write the reaction of chloroform with silver powder.
Chloroform reacts with silver powder to produce acetylene (C₂H₂).
- 2CHCl₃ + 6Ag → C₂H₂ + 6AgCl
10. What precautions should be taken while handling chloroform?
Precautions are essential while handling chloroform due to its toxicity.
- Work in a well-ventilated area or a fume hood.
- Avoid direct inhalation and skin contact; use gloves and goggles.
- Store in tightly-sealed, dark containers with ethanol.
11. How can you test for the presence of chloroform?
Chloroform can be identified using the isocyanide test.
- When chloroform is heated with ethanolic solution of aniline and KOH, a foul-smelling isocyanide is formed, confirming its presence.
