Na2B4O7.10H2O; a hydrated salt of boric acid. It forms insoluble salts with Ca2+ and Mg2+ ions, and thus is useful as a water softener and cleanser. Borax in a less hydrated form (4H2O) is the most important source of boron. It is an important ingredient in borosilicate (Pyrex(r)) glasses.
(Discuss)Borax is a somewhat generic name used to describe a number of closely related minerals or chemical compounds:
Anhydrous borax (Na2B4O7) Borax pentahydrate (Na2B4O7·5H2O) Borax decahydrate (Na2B4O7·10H2O)The term borax is most often used to describe borax decahydrate.
The name comes from Arabic būraq or bauraq بورق which in turn comes from Middle Persian Burag.
Borax, also called sodium borate or sodium tetraborate, is an important boron compound.
Borax occurs naturally in evaporite deposits produced by the repeated evaporation of seasonal lakes (see playa).
Borax is widely used in detergents, water softeners, soaps, disinfectants, and pesticides. It is used in making enamel glazes, glass and strengthening pottery and ceramics. It is also used to make buffer solutions that are used in chemical analysis.
Large amounts of borax pentahydrate are used for manufacturing insulating fibreglass and cellulose insulation as a fire retardant and anti-fungal compound. Large amounts are also used in production of sodium perborate monohydrate for use in detergents.
A mixture of borax and ammonium chloride is used as a flux when welding iron and steel. Borax is also used mixed with water as a flux when soldering jewelry metals such as gold or silver.
When used in a mixture, borax can be used to kill carpenter ants and fleas.
The origin of the name is traceable to the Persian word bürah. The word was also used disparagingly in the 1940s to refer to tawdry modernistic furniture and other works of industrial design.
Borax is also a food additive in some countries (it is banned in the United States), with E number E285.
Boric acid, Sodium Borate, and Sodium Perborate are estimated to have a fatal dose from 0.1 to 0.5g/kg (Handbook of Poisoning, Robert H. Boric acid solutions used as an eye wash or abraded skin is known to be especially toxic to infants, especially after repeated use due to its slow elimination rate(Goodman and Gillman's: The Pharmacological Basis of Therapeutics, 6th edition,chapter on Antiseptics and Disinfectants, page 971).
Structure
Borax is generally described as Na2B4O7·10H2O.
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