Bromoform

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Bromoform
Names
IUPAC name
Tribromomethane
Other names
Methane tribromide
Methenyl tribromide
Methyl tribromide
Properties
CHBr3
Molar mass 252.731 g/mol
Appearance Clear colorless liquid
Odor Sweet, typical halocarbon
Density 2.8912 g/cm3 (20 °C)
Melting point 8.3 °C (46.9 °F; 281.4 K)
Boiling point 149.5 °C (301.1 °F; 422.6 K)
0.1 g/100 ml (20 °C)
Solubility Miscible with acetone, benzene, chloroform, DCM, diethyl ether, ethanol, hexane, methanol, oils, petroleum ether, pyridine, toluene, xylene
Vapor pressure 5.025 mmHg at 20 °C
Acidity (pKa) 13.7
Thermochemistry
6.1–12.7 kJ/mol
Hazards
Safety data sheet Sigma-Aldrich
Lethal dose or concentration (LD, LC):
933 mg/kg (rat, oral)
1,151 ppm (mammal)
Related compounds
Related compounds
Chloroform
Iodoform
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Bromoform is a brominated organic solvent, colorless liquid at room temperature, with a high refractive index, very high density, and sweet odor is similar to that of chloroform. It is one of the four haloforms, the others being fluoroform, chloroform and iodoform. Bromoform has the chemical formula CHBr3.

Properties

Chemical

Partial reduction of bromoform yields dibromomethane.

Physical

Bromoform is a dense colorless liquid at standard conditions, with a high refractive index, with a sweet odor typical of halocarbons and immiscible with water and polar solvents, but miscible with most non-polar solvents.

Availability

Bromoform is sold by chemical suppliers.

Small amounts of bromoform are produced by seaweed.

Preparation

Bromoform can be prepared by the haloform reaction using a methyl ketone like acetone and sodium hypobromite.

(CH3)2C=O + 3 NaOBr → CHBr3 + 2 NaOH + CH3COONa

Sodium hypobromite can be prepared by adding bromine to sodium hydroxide.

Other routes involve the electrolysis of potassium bromide in ethanol, or by treating chloroform with aluminium bromide.

Projects

  • Extraction solvent
  • Separation of minerals by density
  • Compound collecting

Handling

Safety

Bromoform is harmful and exposure may cause irritation to the respiratory tract, the eyes and the skin, and may cause effects on the central nervous system and liver, resulting in impaired functions. It can be absorbed into the body by inhalation and through the skin.

The International Agency for Research on Cancer (IARC) concluded that bromoform is not classifiable as to human carcinogenicity, however the EPA classifies bromoform as a probable human carcinogen.

Storage

In closed amber glass bottles with a suitable cap, in a dark place away from heat and light. Ethanol is sometimes used as stabilizer.

Disposal

Bromoform should be first diluted, before destroyed with a solution of sodium hydroxide.

References

Relevant Sciencemadness threads