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|Section2= |Section3= |Section6= |Section7= |Section8= }} Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. Powdered borax is white, consisting of soft colorless crystals that dissolve easily in water. Borax has a wide variety of uses. It is a component of many detergents, cosmetics, and enamel glazes. It is also used to make buffer solutions in biochemistry, as a fire retardant, as an anti-fungal compound, in the manufacture of fiberglass, as a flux in metallurgy, neutron-capture shields for radioactive sources, a texturing agent in cooking, and as a precursor for other boron compounds. In artisanal gold mining, the borax method is sometimes used as a substitute for toxic mercury in the gold extraction process. Borax was reportedly used by gold miners in parts of the Philippines in the 1900s.〔http://www.blacksmithinstitute.org/newsletter/march-april-filipino-gold-miner-reveals-borax-secret-pakistan-s-pollution-problem.html#topic1〕 The term ''borax'' is used for a number of closely related minerals or chemical compounds that differ in their crystal water content, but usually refers to the decahydrate. Commercially sold borax is partially dehydrated. The word ''borax'' is from Arabic ' (), meaning "white"; which is from Middle Persian ', which might have meant potassium nitrate or another fluxing agent, now known as ' (). Another name for borax is tincal, from Sanskrit.〔(【引用サイトリンク】title=Borax ( Na2B4O7. 10H2O ) – Sodium Borate – Occurrence, Discovery and Applications )〕 Borax was first discovered in dry lake beds in Tibet and was imported via the Silk Road to Arabia.〔 Borax first came into common use in the late 19th century when Francis Marion Smith's Pacific Coast Borax Company began to market and popularize a large variety of applications under the 20 Mule Team Borax trademark, named for the method by which borax was originally hauled out of the California and Nevada deserts in large enough quantities to make it cheap and commonly available.〔"American Borax Production" Scientific American September 22, 1877〕〔Hildebrand, G. H. (1982) "Borax Pioneer: Francis Marion Smith." San Diego: Howell-North Books. p. 267 ISBN 0-8310-7148-6〕 == Chemistry == The term ''borax'' is often used for a number of closely related minerals or chemical compounds that differ in their crystal water content: * Anhydrous borax (Na2B4O7) * Borax pentahydrate (Na2B4O7·5H2O) * Borax decahydrate (Na2B4O7·10H2O) Borax is generally described as Na2B4O7·10H2O. However, it is better formulated as Na2()·8H2O, since borax contains the ()2− ion. In this structure, there are two four-coordinate boron atoms (two BO4 tetrahedra) and two three-coordinate boron atoms (two BO3 triangles). Borax is also easily converted to boric acid and other borates, which have many applications. Its reaction with hydrochloric acid to form boric acid is: : Na2B4O7·10H2O + 2 HCl → 4 H3BO3 + 2 NaCl + 5 H2O The "decahydrate" is sufficiently stable to find use as a primary standard for acid base titrimetry.〔 p. 316.〕 When borax is added to a flame, it produces a yellow green color. Borax is not used for this purpose in fireworks due to the overwhelming yellow color of sodium. Boric acid is used to color methanol flames a transparent green. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「borax」の詳細全文を読む スポンサード リンク
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