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|Section2= |Section3= |Section7= |Section8= }} Hydrazoic acid, also known as hydrogen azide or azoimide, is a colorless, volatile, and explosive liquid at room temperature and pressure. It is a compound of nitrogen and hydrogen, having chemical formula HN3. It was first isolated in 1890 by Theodor Curtius. The acid has few applications, but its conjugate base, the azide ion, is useful in specialized processes. Hydrazoic acid is soluble in water. Undiluted hydrazoic acid is dangerously explosive with a standard enthalpy of formation ΔfHo (l, 298K) = +264 kJmol−1).〔 When dilute, the gas and aqueous solutions (<10%) can be safely handled. ==Production== The acid is usually formed by acidification of an azide salt like sodium azide. Normally solutions of sodium azide in water contain trace quantities of hydrazoic acid in equilibrium with the azide salt, but introduction of a stronger acid can convert the primary species in solution to hydrazoic acid. The pure acid may be subsequently obtained by fractional distillation as an extremely explosive colorless liquid with an unpleasant smell. :NaN3 + HCl → HN3 + NaCl Its aqueous solution can also be prepared by treatment of barium azide solution with dilute sulfuric acid, filtering the insoluble barium sulfate.〔L . F. Audrieth, C. F. Gibbs Hydrogen Azide in Aqueous and Ethereal Solution" Inorganic Syntheses 1939, vol. 1, pp. 71-79.〕 It was originally prepared by the reaction of aqueous hydrazine with nitrous acid. :N2H5+ + HNO2 → HN3 + H+ + 2 H2O Other oxidizing agents, such as hydrogen peroxide, NOCl, NCl3 or nitric acid, can also be used. 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「Hydrazoic acid」の詳細全文を読む スポンサード リンク
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