Hydrogen bromide

 

Hydrogen bromide

Chemical formula	HBr
OTP appearance	colorless/faint yellow gas
Index of refraction	1.325
Molar Mass(g/mol)	80.91
Density(g/cc)	0.0036452
Melting Point(°C)	-86.9
Boiling Point(°C)	-66.8
Solubility in water(g/L)	1930
NFPA 704	0 3 0

Uses

Primary

• Key chemical intermediate for bromine chemistry.

Natural occurrence

• does not occur naturally.

Hazards

• HBr is highly corrosive and irritating to inhalation.

Production

Synthesis

• Combine sodium bromide and sulfuric acid:

  NaBr + H₂SO₄ → NaHSO₄ + HBr

• React bromine with water and sulfur:

  2 Br₂ + S + 2 H₂O → 4 HBr + SO₂

• React bromine with water and sodium metabisulfate giving hydrobromic acid and sodium bisulfate

  Na₂S₂O₅ + 2 Br₂ + 3 H₂O → 2 NaHSO₄ + 4 HBr

Purification

Bromine contamination can be removed by passing the gas through a solution of phenol dissolved in carbon tetrachloride at room temperature

HBr(v) + Br₂(v) + CCl₄(l) + C₆H₅OH(diss) → 2 HBr(v) + CCl₄(l) + C₆H₄OHBr(diss)