refluxing xylene. Hydrogen bromide prepared by the above methods can be contaminated with Br2, which can be removed by passing the gas through a solution of phenol at room temperature in tetrachloromethane or other suitable solvent (producing 2,4,6-tribromophenol and generating more HBr in the process) or through copper turnings or copper gauze at high temperature. Safety HBr is highly corrosive and irritating to inhalation. References Inorganic compounds Hydrogen compounds Bromides Nonmetal halides Diatomic molecules