Bromoform
Bromoform, also known as tribromomethane, is a colorless to yellow liquid with a chloroform-like odor. It is a haloform, specifically a trihalomethane with the chemical formula CHBr₃. Bromoform is a dense liquid, heavier than water, and is slightly soluble in water but soluble in most organic solvents.
Properties:
- Chemical Formula: CHBr₃
- Molar Mass: 252.73 g/mol
- Appearance: Colorless to yellow liquid
- Odor: Chloroform-like
- Density: 2.89 g/cm³
- Melting Point: 8.3 °C
- Boiling Point: 149.5 °C
- Solubility in water: Slightly soluble
- Refractive Index: 1.5981
Occurrence and Production:
Bromoform is found naturally in some marine algae, which produce it through metabolic processes. Commercially, it is produced primarily by the haloform reaction, which involves the reaction of acetone (or ethanol) with hypobromite. It can also be produced by the bromination of methane.
Uses:
Historically, bromoform was used as a solvent, sedative, and cough suppressant. However, due to its toxicity and potential health hazards, its use in these applications has been largely discontinued. Currently, bromoform is primarily used as a laboratory reagent, particularly in geological research for mineral separation due to its high density. It has also been investigated for potential applications in the synthesis of other chemicals.
Safety and Environmental Concerns:
Bromoform is considered a hazardous substance. Exposure can occur through inhalation, ingestion, or skin contact. It can cause irritation to the skin, eyes, and respiratory system. Prolonged exposure can lead to liver and kidney damage. It is classified as possibly carcinogenic to humans by the International Agency for Research on Cancer (IARC).
Bromoform is an environmental contaminant and is regulated as a disinfection byproduct in drinking water. Its presence in drinking water is typically due to the reaction of chlorine (or other disinfectants) with organic matter in the water source. Its volatility means it can also be found in air. Regulations are in place to limit its concentration in drinking water to minimize human exposure.