Barium Chloride,2 hydrate (250gr)

Barium Chloride,2 hydrate (250gr)

Barium Chloride is an inorganic compound with the formula BaCl₂. It is one of the most common water-soluble salts of barium. Like most other water-soluble barium salts, it is white, highly toxic, and imparts a yellow-green coloration to a flame. It is also hygroscopic, converting first to the dihydrate BaCl₂(H₂O)₂. It has limited use in the laboratory and industry.

Structure and properties

BaCl₂ crystallizes in two forms (polymorphs). One form has the cubic fluorite (CaF₂) structure and the other the orthorhombic cotunnite (PbCl₂) structure. Both polymorphs accommodate the preference of the large Ba²⁺ ion for coordination numbers greater than six. The coordination of Ba²⁺ is 8 in the fluorite structure and 9 in the cotunnite structure. When cotunnite-structure BaCl₂ is subjected to pressures of 7–10 GPa, it transforms to a third structure, a monoclinic post-cotunnite phase. The coordination number of Ba²⁺ increases from 9 to 10.

In aqueous solution BaCl₂ behaves as a simple salt; in water it is a 1:2 electrolyte and the solution exhibits a neutral pH. Its solutions react with sulfate ion to produce a thick white precipitate of barium sulfate. Ba²⁺ + SO²⁻₄ → BaSO₄

Oxalate effects a similar reaction: Ba²⁺ + C₂O²⁻₄ → BaC₂O₄

When it is mixed with sodium hydroxide, it gives the dihydroxide, which is moderately soluble in water.

Preparation

On an industrial scale, it is prepared via a two step process from barite (barium sulfate): BaSO₄ + 4 C → BaS + 4 CO

This first step requires high temperatures.

BaS + 2 HCl → BaCl₂ + H₂S

In place of HCl, chlorine can be used.

Barium chloride can in principle be prepared from barium hydroxide or barium carbonate. These basic salts react with hydrochloric acid to give hydrated barium chloride.

Uses

Although inexpensive, barium chloride finds limited applications in the laboratory and industry. In industry, barium chloride is mainly used in the purification of brine solution in caustic chlorine plants and also in the manufacture of heat treatment salts, case hardening of steel. It is also used to make red pigments such as Lithol red and Red Lake C. Its toxicity limits its applicability.

Safety

Barium chloride, along with other water-soluble barium salts, is highly toxic. Sodium sulfate and magnesium sulfate are potential antidotes because they form barium sulfate BaSO₄, which is relatively non-toxic because of its insolubility.