Хлорид бария

Описание

Barium dichloride is a white solid, odorless, hygroscopic chemical substance. Barium dichloride is used in the manufacture of pigments, in the manufacture of other barium salts and in fireworks to give a bright green color. It is one of the most common watersoluble salts of barium. Like other barium salts, it is toxic and imparts a yellow-green coloration to a flame. Barium chloride has wide application in the laboratory.

Химические свойства

Barium chloride,BaCI2, is a colorless toxic salt with a melting point of 963°C. It is soluble in water. Barium chloride is used in metal surface treatment and as a rat poison.

Физические свойства

Barium chloride has the formula, BaCl2 and is an ionic chemical compound. It is one of the most important water-soluble salts of barium-containing compounds. Like other barium salts, it is toxic and imparts a yellow-green coloration to a flame. It is also hygroscopic. Barium chloride was the by-product of the discovery of radium by Madame Curie (1898).When refining radium, the final separation resulted in barium chloride and radium chloride. BaCl2 crystallizes in both the cubic “fluorite” and “lead chloride” crystal structures, both of which accommodate the preference of the large Ba²⁺ ion for coordination numbers greater than six.

Подготовка

Barium chloride can be prepared from barium hydroxide or barium carbonate, the latter being found naturally as the mineral “Witherite”. These basic salts react to give hydrated barium chloride. On an industrial scale, it is prepared via a two-step process from the mineral “Baryte”:
BaSO4＋4C→BaS＋4CO (gas)
This first step requires high temperatures. The second step requires fusion of the reactants:
BaS＋ CaCl2→BaCl2＋CaS
The BaCl2 is then be leached out from the mixture with water. From water solutions of barium chloride, the dihydrate can then be crystallized as white crystals, BaCl2·2H2O, which are colorless, translucent rhomboidal tablets or lamellae. The dihydrate is stable in the air at room temperature, but loses one-half of its water above 55°C(131F), and becomes anhydrous at 121°C (250 F).

Общее описание

Any of a variety of substances that contain barium. Most are whitish colored crystalline solids. They tend to be soluble in water and denser than water. They may be toxic by inhalation or possibly skin absorption. They are often used to make other chemicals.

Реакции воздуха и воды

Water soluble.

Профиль реактивности

BARIUM CHLORIDE may react violently with BrF3 and 2-furan percarboxylic acid in its anhydrous form.

Опасность

Ingestion of 0.8 g may be fatal.

Пожароопасность

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.

Промышленное использование

Barium chloride (BaCl₂·2H₂O) is a colorless, white powder highly soluble in water (25% at 10 °C). It is quite a toxic reagent. Barium chloride is used during borite flotation as an activator. Barium chloride also has a depressing effect on fluorite and cassiterite.

Профиль безопасности

A poison by ingestion, subcutaneous, intravenous, and intraperitoneal routes. Inhalation absorption of barium chloride equals 60-80%; oral absorption equals 10-30%. Experimental reproductive effects. Mutation data reported. See also BARIUM COMPOUNDS (soluble). When heated to decomposition it emits toxic fumes of Cl-.