Barium sulfate CAS#7727-43-7

Product Description of Direct Pigment Yellow 42 (CAS# 51274-00-1)

Barium sulfate, with the chemical formula BaSO₄, appears as colorless or white orthorhombic crystals. It has a relative molecular mass of 233.4, a density of 4.5 (15°C), a melting point of 1580°C, and a refractive index of 1.637. When heated to 1149°C, it transforms into a monoclinic crystal form with a refractive index of 1.649.

It is almost insoluble in water, with a solubility of 0.00022 at 18°C and 0.0041 at 100°C. It is slightly soluble in concentrated sulfuric acid and soluble in carbonate alkali metal solutions, where it converts to barium carbonate, while remaining insoluble in most other acids and bases. In nature, it occurs in the form of the mineral barite. When heated with carbon (pulverized coal) to 800°C, it is reduced to soluble barium sulfide and carbon monoxide.

Barium sulfate has excellent X-ray absorption properties, making it impermeable to X-rays. For this reason, it is widely used in medicine as a barium meal agent for gastrointestinal and stomach X-ray examinations. It is also the only non-toxic barium salt, which makes it suitable for analytical reagents, electronics, instrumentation, metallurgy, and other industrial applications. In addition, it can be used as a white pigment, a contrast agent for stomach X-ray angiography, a copper flux, a drilling mud weighting agent, and a filler for rubber, paper, and plastics. It is produced through the reaction of sulfuric acid and barium chloride.

Barium sulfate Chemical Properties

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