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Boranes

Borane is the collective name for a sequence of chemical compounds used in science and industry. The highly reactive boranes consist primarily of the elements boron and hydrogen, but some derived compounds are called boranes as well. Boranes were first studied intensively by a German chemist, Alfred Stock, early in the 20th century. Since then, boranes have been used in the preparation of silicone rubber and for other polymerization processes. They also serve as high-energy fuels. Boranes are rather unstable, and the lighter ones, such as diborane (B₂H₆), may explode on contact with air. Diborane can be used to produce boranes of higher molecular weight, such as deca borane (B₁₀H₁₄), and to form coatings of pure boron for various technological devices.

Borax

Borax, or sodium tetraborate, Na₂B₄O₇· 10H₂O, is a chemical compound, crystallizing in the monoclinic system, with hardness 2 and specific gravity 1.7. When heated it swells, gives off water, and fuses easily, forming a glasslike mass. Mineral borax was discovered in ancient times in Tibet and was exported to Europe under the name tincal. In modern times, this source was replaced by extensive deposits of borax and related minerals in California; Stassfurt, Germany; Tuscany, Italy; and the Atacama Desert, Chile. The mineral kernite, or rasorite, Na₂B₄O₇· 4H₂O, is identical with borax except for water content, hardness (3), and specific gravity (1.95). Borax dissolves readily in water, forming an alkaline, antiseptic solution that is used as a disinfectant, detergent, and water softener. It is an excellent flux for soldering and welding because it dissolves the coating of metallic oxide to leave a clean metal surface. Borax beads are used in chemical laboratories for analytical purposes; when melted with borax, different metallic oxides form beads of differently colored borates. Borax also is used in the manufacture of ceramics, enamel, and glass. Pyrex glass contains 30% borax by weight. In making such products as paint, calcimine, and coated paper, borax is combined with the plastic casein.

Boric Acid

Boric Acid is a white crystalline powder with formula H₃BO₃. Although boric acid is poorly soluble in water at room temperature (1 g dissolving in 18 g water), it dissolves readily in hot water (1 g dissolving in less than 4 g water) and in alcohol and glycerin. It is slightly volatile in steam. A significant amount of boric acid appears in some natural steam vents, especially in Tuscany (Toscana), Italy, but free boric acid is not otherwise found in nature. Its salts, however, occur in many places. Boric acid can be easily prepared by treating borax with sulfuric acid. Boric acid in solution is only slightly acidic and acts as a nonirritating, slightly astringent antiseptic, mild enough to be used as eyewash. Commercially, boric acid is used in glazing pottery, in fireproofing cloth, in making electroplating baths and artificial gems, and in hardening steels.

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