Hydrobromic Acid, — Chambers's Encyclopaedia

Hydrobromic Acid, (1) gas, $\text{HBr}$ , invisible, pungent, acid reaction, fumes in moist air, liquid at $-69^\circ\text{C}$ ., solid at $-100^\circ\text{C}$ .; prepared from a bromide plus phosphoric acid, or phosphorus tribromide plus water. (2) Aqueous solution, analogous to commercial hydrochloric acid, is weakened by boiling until $\text{HBr}$ sinks to 47 per cent., then distils unchanged. See BROMINE.