ozone

O ₃ (47.9982). An allotrope of oxygen, it is a colorless gas with a characteristic odor at room temperature. Its liquid color is dark blue, and its solid color is blackish blue. It is produced by exposing air or oxygen to ultraviolet light or radiation, or by electric discharge, so it can also be found in the atmosphere. Its melting point is -192.7 °C, its boiling point is -111.9 °C, and its critical temperature is -12.10 °C. Its first ionization energy is 1209 kJ mol ^-1 (12.53 eV). Its solubility in water is low, at 49 mL per 100 mL (0 °C). It is soluble in liquid nitrogen, but is almost immiscible with liquid oxygen. Its molecule is an isosceles triangle with a vertex angle of 116.79°. The interatomic distance between the two equal sides is OO 0.127 nm. It slowly decomposes to oxygen at room temperature. Manganese dioxide and platinum powder accelerate the decomposition. It has a strong oxidizing power and oxidizes silver and mercury at room temperature to silver peroxide and mercury oxide. When it is passed through a potassium iodide solution, it liberates iodine. The concentration of iodine produced by this reaction is determined by absorption photometry and used to quantify ozone (potassium iodide method, JIS B 7957). Because of its strong oxidizing power, it is used in bleaching, drinking water and sewage treatment, chemical synthesis, etc. Even if it is present in the air at 1 to 2 ppm, breathing it for 2 hours can cause headaches and chest pains. It does not irritate the eyes. Animal experiments have shown that it is dangerous to the human body even for a short period of time at 50 to 60 ppm. Under the Industrial Safety and Health Act and its Enforcement Order, it is designated as a "substance that may cause health damage to workers" and a "hazardous and harmful substance whose name, etc. must be notified" to the party to whom it is transferred or provided. To quantify trace amounts of ozone in the air, the chemiluminescence method using reaction with ethene and the ultraviolet absorption method (254 nm) are used. The total amount of ozone in the atmosphere is estimated by measuring the ultraviolet light from the sun that reaches the earth's surface using a spectrophotometer, and comparing the wavelength dependence of the absorption intensity of ozone with the absorption wavelength intensity ratio of ozone. [CAS 10028-15-6][See other terms] Photochemical oxidant, photochemical smog

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

O₃(47.9982)．酸素の同素体で，常温で特異臭をもつ無色の気体．液体は暗青色，固体は黒青色．空気または酸素の紫外線・放射線照射，放電により生成するので，大気中に存在することもある．融点－192.7 ℃，沸点－111.9 ℃，臨界温度－12.10 ℃．第一イオン化エネルギー1209 kJ mol^－1(12.53 eV)．水に対する溶解度は低く，100 mL に対する溶解度は49 mL(0 ℃)．液体窒素には可溶であるが，液体酸素とはほとんどまじらない．分子は二等辺三角形型で頂角116.79°．等しい二辺の原子間距離O-O 0.127 nm．常温で徐々に分解して酸素となる．二酸化マンガン，白金粉末などは分解を速める．酸化力が強く常温で銀，水銀を酸化して過酸化銀，酸化水銀とする．ヨウ化カリウム溶液に通じるとヨウ素を遊離する．この反応で生成するヨウ素濃度を吸光光度法で決定して，オゾン定量に用いる(ヨウ化カリウム法，JIS B 7957)．酸化力が強いため，漂白，飲料水・下水などの処理，化学合成上などで用いられる．空気中に1～2 ppm 含まれていても2時間呼吸すると，頭痛や胸痛をもたらす．眼は刺激しない．動物実験により50～60 ppm で短時間でも人体に危険とされている．労働安全衛生法・同施行令により，「労働者に健康障害を生ずるおそれのある物」で，譲渡し，または提供する相手方に「名称等を通知すべき危険物及び有害物」に指定されている．大気中の微量オゾンの定量には，エテンとの反応による化学発光法と紫外線吸収法(254 nm)が用いられる．大気中に含まれるオゾン全量の推定は，地表に到達する太陽からの紫外光を分光光度計により分光して，オゾンによる吸収強度の波長依存性をオゾンの吸収波長強度比と比較して行う．[CAS 10028-15-6][別用語参照]光化学オキシダント，光化学スモッグ

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