Title: Hydrobromic Acid
CAS Registry Number: 10035-10-6
Molecular Formula: HBr
Molecular Weight: 80.91
Percent Composition: H 1.25%, Br 98.76%
Literature References: A soln of hydrogen bromide gas in water. Marketed in various concns, e.g., 50% HBr, d 1.517; 40% HBr, d 1.38; 34%, d 1.31; 10%, d 1.08. Lab prepn according to the eq H2SO4 + KBr ® KHSO4 + HBr: Heisig, Amdur, Inorg. Synth. 1, 155 (1939). See also Hydrogen Bromide.
Properties: Colorless or faintly yellow; slowly darkens on exposure to air and light. Miscible with water, alcohol. Keep protected from light. When dil hydrobromic acid is distilled, a weaker acid comes over first and when a very concd acid is boiled, HBr gas chiefly distills over first; in both cases a "constant boiling" acid contg about 47.5% HBr remains which distills unchanged at 126°. The bp and compn of the azeotrope varies with pressure: at 100 mm, bp 74.12°, compn 49.80% HBr; at 400 mm, bp 107.00°, compn 48.47%; at 700 mm, bp 122°, compn 47.74%; at 800 mm, bp 125.79°, compn 47.56%: Bonner et al., J. Am. Chem. Soc. 55, 1406 (1933). Aq solns are strongly acid. The satd aq soln contains 68.85% HBr at 0° and 66% at 25°.
Boiling point: at 100 mm, bp 74.12°, compn 49.80% HBr; at 400 mm, bp 107.00°, compn 48.47%; at 700 mm, bp 122°, compn 47.74%; at 800 mm, bp 125.79°, compn 47.56%
CAUTION: Strong irritant.
Use: The concd acid is used principally in analytical chemistry and organic prepns.
Therap-Cat: Sedative.
Therap-Cat-Vet: Has been used as a sedative.
Keywords: Sedative/Hypnotic. |