Barium bromide is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

BaBr₂. It is ionic and

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

in nature.

Structure and properties

BaBr₂ crystallizes in the lead chloride ( cotunnite) motif, giving white

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic Lattice (group), lattices result from stretching a cubic crystal system, cubic lattice along two of its orthogonal pairs by two different factors, res ...

crystals A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macrosc ...

that are

deliquescent Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

. In aqueous solution BaBr₂ behaves as a simple

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

. Solutions of barium bromide reacts with the

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

salts In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...

to produce a solid

precipitate In an aqueous solution, precipitation is the "sedimentation of a solid material (a precipitate) from a liquid solution". The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemic ...

barium sulfate Barium sulfate (or sulphate) is the inorganic compound with the chemical formula Ba SO4. It is a white crystalline solid that is odorless and insoluble in water. It occurs in nature as the mineral barite, which is the main commercial source of ...

. :BaBr₂ + → BaSO₄ + 2 Br⁻ Similar reactions occur with

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and chemical formula , also written as or or . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name i ...

hydrofluoric acid Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colorless, acidic and highly corrosive. A common concentration is 49% (48–52%) but there are also stronger solutions (e.g. 70%) and pure HF has a boiling p ...

, and

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...

, giving solid precipitates of barium oxalate, fluoride, and phosphate, respectively.

Preparation

Barium bromide can be prepared by treating

barium sulfide Barium sulfide is the inorganic compound with the formula Ba S. BaS is the barium compound produced on the largest scale. It is an important precursor to other barium compounds including barium carbonate and the pigment lithopone, ZnS/BaSO4. ...

barium carbonate Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of ...

with hydrobromic acid: :BaS + 2 HBr → BaBr₂ + H₂S :BaCO₃ + 2 HBr → BaBr₂ + CO₂ + H₂O Barium bromide crystallizes from concentrated aqueous solution in its di

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

, BaBr₂·2H₂O. Heating this dihydrate to 120 °C gives the

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...

salt.

Uses

Barium bromide is a precursor to chemicals used in photography and to other

bromide A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retard ...

s.
Historically, barium bromide was used to purify

radium Radium is a chemical element; it has chemical symbol, symbol Ra and atomic number 88. It is the sixth element in alkaline earth metal, group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, ...

in a process of fractional crystallization devised by

Marie Curie Maria Salomea Skłodowska-Curie (; ; 7 November 1867 – 4 July 1934), known simply as Marie Curie ( ; ), was a Polish and naturalised-French physicist and chemist who conducted pioneering research on radioactivity. She was List of female ...

. Since radium precipitates preferentially in a solution of barium bromide, the ratio of radium to barium in the precipitate would be higher than the ratio in the solution.

Safety

Barium bromide, along with other water-soluble barium salts (e.g.

barium chloride Barium chloride is an inorganic compound with the formula . It is one of the most common water-soluble salts of barium. Like most other water-soluble barium salts, it is a white powder, highly toxic, and imparts a yellow-green coloration to a flam ...

), is toxic. However, there is no conclusive data available on its hazards.https://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do?country=US&language=en&productNumber=413607&brand=ALDRICH ,

In popular culture

The compound appears in the intro title card of

Breaking Bad ''Breaking Bad'' is an American crime drama television series created and produced by Vince Gilligan for AMC (TV channel), AMC. Set and filmed in Albuquerque, New Mexico, the series follows Walter White (Breaking Bad), Walter White (Bryan Cran ...

, where the first pairs of letters are replaced with Br³⁵ and Ba⁵⁶, the symbols and

atomic number The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of its atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (''n''p) or the number of pro ...

s of

bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between th ...

and

barium Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. Th ...

respectively.

References

{{Authority control Bromides Alkaline earth metal halides Barium compounds