Бромистый водород химические свойства, назначение, производство
Описание
Hydrobromic Acid is a strong acid formed by dissolving the
diatomic molecule HBr in water. “Constant-boiling”
hydrobromic acid is an aqueous solution that distills at
124.3°C and contains 47.6% HBr by weight. Hydrobromic
acid has a pKa of 9, making it a stronger acid
than hydrochloric acid, but not as strong as HI, hydroiodic
acid. Hydrobromic acid is one of the strongest
mineral acids known.
Hydrobromic acid is mainly used for the production
of inorganic bromides, especially the bromides of zinc,
calcium, and sodium. It is a useful reagent for generating
organobromine compounds. Certain ethers are
cleaved with HBr. It also catalyzes alkylation reactions
and the extraction of certain ores. Industrially significant
organic compounds prepared from hydrobromic
acid include allyl bromide, tetrabromobis(phenol),
and bromoacetic acid.
Hydrobromic acid can be prepared in the laboratory
via the reaction of Br2, SO2 and water. Another laboratory
preparation involves the production of anhydrous
HBr, which is then dissolved in water.
Hydrobromic acid has commonly been prepared
industrially by reacting bromine with either sulfur or
phosphorous and water. However, it can also be
produced electrolytically. It can also be prepared by
treating bromides with nonoxidizing acids like phosphoric
or acetic acids. Hydrobromic acid is available
commercially in various concentrations and purities.
Химические свойства
colourless liquid with a strong irritating odour
Физические свойства
Colorless gas; fumes in moist air; pungent acrid odor; nonflammable; heav-ier than air; density 2.71 (air=1.0); gas density 3.55 g/L at 25°C; liquefies at-66.4°C; solidifies at -86.8°C; critical temperature 89.8°C; critical pressure84.5 atm; highly soluble in water (saturated aqueous solution contains 66%HBr at 25°C); forms a constant-boiling azeotrope at 47.5% HBr in solution,boiling at 126°C at atmospheric pressure; soluble in alcohol; a 0.10Maqueoussolution is 93% ionized to H+and Br ? ions at 18°C.
Использование
Hydrogen bromide is used as a reagent and
catalyst in several types of organic reactions
such as the formation of alkyl bromides from
alcohols.
It is also used as a source material in the
preparation of inorganic bromides. Hydrogen
bromide serves as a catalyst in alkylation reactions.
It has also been reportedly used in the
controlled oxidation of aliphatic and alicyclic
hydrocarbons to peroxides, ketones, and acids.
In organic synthesis, hydrogen bromide is used
to substitute bromine for aliphatic chlorine in
the presence of aluminum catalyst.
Определение
Hydrogen bromide in aqueous solution.
Подготовка
Hydrogen bromide gas may be produced by combustion of hydrogen inbromine vapor at 37.5°C using a catalyst such as platinized asbestos or pla-tinized silica gel. Unreacted free bromine is removed from the product bypassing the gaseous product mixture over hot activated charcoal. Hydrogenbromide formed may be absorbed in water to obtain the acid; or may be cooledand liquefied for shipment in cylinders.
Hydrobromic acid may be prepared in the laboratory by distillation of asolution of potassium bromide with dilute sulfuric acid:
2KBr + H2SO4 → K2SO4 + HBr
The acid may be prepared by several other methods, as well, including reac-tion of bromine either with sulfur and water; or with phosphorus and water:
2Br2 + S + 2H2O → 4HBr + SO2
Hydrobromic acid also may be prepared by hydrogen exchange with a sodiumor potassium bromide solution when the solution is passed through a cation-exchange resin.
Hydrobromic acid is stored and shipped in drums, tanks, carboys, or bot-tles, labeled as corrosive materials. The anhydrous gas is stored and shippedin cylinders under its vapor pressure.
Общее описание
Hydrobromic acid solution (HBr) is a clear, yellow or brown colored liquid. Its reaction with K has been studied by a molecular beam technique.
Реакции воздуха и воды
Acrid odor, fumes in moist air forming clouds containing hydrobromic acid. Heat of solution large, [Merck, 11th ed., 1989].
Профиль реактивности
HYDROGEN BROMIDE is an anhydrous (no water) strong acid. Reacts rapidly and exothermically with bases of all kinds (including amines and amides). Reacts exothermically with carbonates (including limestone and building materials containing limestone) and hydrogen carbonates to generate carbon dioxide. Reacts with sulfides, carbides, borides, and phosphides to generate toxic or flammable gases. Reacts with many metals (including aluminum, zinc, calcium, magnesium, iron, tin and all of the alkali metals) to generate flammable hydrogen gas. Reacts violently with acetic anhydride, 2-aminoethanol, ammonium hydroxide, calcium phosphide, chlorosulfonic acid, 1,1-difluoroethylene, ethylenediamine, ethyleneimine, oleum, perchloric acid, b-propiolactone, propylene oxide, silver perchlorate/carbon tetrachloride mixture, sodium hydroxide, uranium(IV) phosphide, vinyl acetate, calcium carbide, rubidium carbide, cesium acetylide, rubidium acetylide, magnesium boride, mercury(II) sulfate, calcium phosphide, calcium carbide.
Опасность
Toxic by inhalation, strong irritant to eyes
and skin.
Угроза здоровью
Hydrobromic acid and hydrogen bromide gas are highly corrosive substances that
can cause severe burns upon contact with all body tissues. The aqueous acid and gas
are strong eye irritants and lacrimators. Contact of concentrated hydrobromic acid or
concentrated HBr vapor with the eyes may cause severe injury, resulting in
permanent impairment of vision and possible blindness. Skin contact with the acid
or HBr gas can produce severe burns. Ingestion can lead to severe burns of the
mouth, throat, and gastrointestinal system and can be fatal. Inhalation of hydrogen
bromide gas can cause extreme irritation and injury to the upper respiratory tract and
lungs, and exposure to high concentrations may cause death. HBr gas is regarded as
having adequate warning properties.
Hydrogen bromide has not been found to be carcinogenic or to show reproductive or
developmental toxicity in humans.
Пожароопасность
Behavior in Fire: Pressurized container may explode and release toxic, irritating vapor.
Воспламеняемость и взрывоопасность
Noncombustible, but contact with metals may produce highly flammable hydrogen
gas.
Использование в материалах
Hydrogen bromide does not aggressively attack
common metals of construction while in the
anhydrous state. However, in the presence of
moisture, hydrogen bromide will attack most
metals except platinum and silver. Galvanized
pipe, brass, and bronze should be avoided.
Steel, Monel, and aluminum-silicon-bronze
have proven satisfactory in anhydrous hydrogen
bromide service.
хранилище
Splash goggles and rubber gloves should be
worn when handling this acid, and containers of HBr should be stored in a wellventilated
location separated from incompatible metals. Water should never be
added to HBr because splattering may result; always add acid to water. Containers of
hydrobromic acid should be stored in secondary plastic trays to avoid corrosion of
metal storage shelves due to drips or spills.
Cylinders of hydrogen bromide
should be stored in cool, dry locations, separated from alkali metals and other
incompatible substances.
Методы очистки
A solution of aqueous HBr ca 48% (w/w, constant boiling) is purified by distilling twice with a little red phosphorus, and the middle half of the distillate is taken. (The azeotrope at 760mm contains 47.8% (w/w) HBr.) [Hetzer et al. J Phys Chem 66 1423 1962]. Free bromine can be removed by Irvine and Wilson's method for HI (see above), except that the column is regenerated by washing with an ethanolic solution of aniline or styrene. Hydrobromic acid can also be purified by aerating with H2S, distilling and collecting the fraction boiling at 125-127o. [Heisig & Andur Inorg Synth I 155 1939.] HARMFUL VAPOURS.
Несовместимости
Hydrobromic acid and hydrogen bromide react violently with many metals with the
generation of highly flammable hydrogen gas, which may explode. Reaction with
oxidizers such as permanganates, chlorates, chlorites, and hypochlorites may
produce chlorine or bromine.
Утилизация отходов
In many localities, hydrobromic acid or the residue from a spill may be disposed of down the drain after
appropriate dilution and neutralization. Otherwise, hydrobromic acid and waste material containing this
substance should be placed in an appropriate container, clearly labeled, and handled according to your
institution's waste disposal guidelines. Excess hydrogen bromide in cylinders should be returned to the
manufacturer. For more information on disposal procedures, see Chapter 7 of this volume.
Бромистый водород препаратная продукция и сырье
сырьё
препарат
8-БРОМОТЕОФИЛЛИН
2- (ДИБРОМАЦЕТИЛ БЕНЗИМИДАЗОЛ ГИДРОБРОМНАЯ КИСЛОТА
METHYL 2-AMINO-2-(4-HYDROXYPHENYL)ACETATE
4-бромпиперидин гидробромид
8-бромоктановая кислота
2-метокси-6-метилбензойная кислота
4,4'-БИС (БРОМЕТИЛ) БИФЕНИЛ
3,8-DIMETHYL-1,10-PHENANTHROLINE
Циклогексиламин гидробромид
2-MERCAPTOPYRIMIDIN-4-OL
1,10-дибромдекан
4-бром-о-ксилола
2-BROMO-1-(4,6-DIMETHOXYPYRIMIDIN-2-YL)ETHANONE
9-бром-9-phenylfluorene
10-МЕТИЛСУЛЬФОНИЛ)КАПРИНОВАЯ КИСЛОТА
5-метилпиридин-3-борная кислота
3-(бромацетил)пиридин гидробромид
2,6-DIAMINO-3-BROMOPYRIDINE
4-Бром-7-хлорхинолин
10 Bromodecanoic кислота
3-фуранкарбоновой кислоты
8-бром-1-октанол
1,1,3,3-ТЕТРАБРОМОАЦЕТОН
Bromosuccinic кислота
3-гидрокси-1-метилпиперидина
4 - (бромацетил) пиридина гидробромид
2-амино-5-бромтиазол моногидробромид
4-Bromo-2,3,5,6-tetrafluoropyridine
4-метилбензил бромид
2-ACETYLAMINO-3-BROMO-5-METHYLPYRIDINE
2-Фтор-N-метилбензиламин
3-Bromo-2,6-diaminopyridine ,95%
1-бром-3,4-дифторбензол
2-Bromo-3-methoxy-6-methylpyridine
2-Bromo-3-hydroxy-6-methylpyridine
[4-(трифторметил)фенил]метансульфанил хлорид
Цинк бромид
1-ГИДРОКСИ-2-БУТАНОН
S-(2-аминоэтил) изотиомочевина дигидробромид
1-гексантиол