出自維基百科,自由嘅百科全書
(由阿摩尼亞跳轉過來)
跳去: 定向搵嘢

(粵拼:on1),又叫做氨氣或者阿摩尼亞,係化合物,分子式係NH3。佢喺室溫下呈氣態,無色兼帶有強烈而刺激嘅氣味密度細過空氣,易溶落,但唔容易解離,佢嘅水溶液係弱鹼性。

氨對陸上生物來講係相當之重要,因為佢係所有食物肥料嘅重要成份,重係所有藥物嘅成份。雖則氨有咁重要而又廣泛嘅用途,但係佢既帶有腐蝕性,亦都有害。2006年,全球就生產咗大約十四億六千五百萬[1]

商業上,都會經常叫氨做「脫水氨」。呢個叫法所強調嘅係氨呢種物質係冇水喺裏頭嘅。氨嘅沸點係−33.34℃,故此液態氨就一定要儲存喺高壓,或者低溫嘅環境。而佢嘅汽化熱都算幾高,即係話如果佢已經係液態嘅話就唔會咁易變返氣態,所以氨可以裝喺普通嘅燒杯同埋放入通風櫃道處理。而「氨水」其實就係氨溶液

結構及基本化學特性[編輯]

氨嘅份子結構三角錐形,而根據價層電子對互斥理論(VSEPR),佢嘅鍵角就係107.8°。中間嘅氮原子本身有五粒最外圍電子,再加埋三粒來自三個氫原子嘅附加電子,佢最外層就會有八粒電子,呢四對電子會排喺氮原子嘅四面,其中三對會用來做鍵對,淨返一對就係孤對電子喇。孤對電子嘅排斥力係大過鍵對電子嘅好多,所以佢就唔會好似想像中嘅正四面體噉鍵角109.5°,而係量度到嘅鍵角107.8°。亦因為呢對孤對電子,氨成為質子接受體,鹽基。 而呢個結構就令到佢有電偶極矩同帶有極性。正正因為佢有極性,又有高嘅建氫鍵能力,所以極易溶混於水。氨其實係一隻弱鹼,佢1.0M水溶液嘅pH值係11.6啫。如果加強酸入去直至變成中性,就會大約有99.4%嘅氨份子會質子化。而溫度同鹽度就會影響NH4+嘅比例喇。NH4+嘅結構就係正四面體,而且亦都同甲烷等電子

大自然含量[編輯]

大氣層之中,氨嘅份量其實僅屬微量,主要來自動植物屍體嘅腐化。另外,喺雨水之中,亦都發現少量氨同;喺火山地區就會搵到氯化銨硫酸銨;至於碳酸氫銨結晶體就會喺巴塔哥尼亞海鳥糞之中搵到。腎臟亦會分泌氨去中和過多嘅酸[2]。而喺海水同所有沃土道,都會發現銨鹽。冥王星木星上面都搵到氨,而天王星就僅有少量。

歷史[編輯]

爾個高壓反應器係巴斯夫1921年喺路德維希港道起嘅。其後,喺德國卡爾斯魯厄大學道重新樹立。

「阿摩尼亞」得名於埃及主神阿蒙希臘化名(Ἄμμων Ammon)。當時,古利比亞阿蒙廟附近有氯化銨礦,正因為好近座廟,羅馬人採後就叫啲礦做「阿蒙鹽」(sal ammoniacus)。[3] 氨鹽好早就為人所知曉,而「Hammoniacus sal」爾個詞亦早見於老普林尼嘅著作[4],雖然唔知爾個詞係埋就等同於新啲嘅「sal-ammoniac」,即氯化銨[5]

In the form of sal-ammoniac (nushadir) ammonia was important to the Muslim alchemists as early as the 8th century, first mentioned by the Persian chemist Jābir ibn Hayyān,[6] and to the European alchemists since the 13th century, being mentioned by Albertus Magnus.[7] It was also used by dyers in the Middle Ages in the form of fermented urine to alter the colour of vegetable dyes. In the 15th century, Basilius Valentinus showed that ammonia could be obtained by the action of alkalis on sal-ammoniac. At a later period, when sal-ammoniac was obtained by distilling the hooves and horns of oxen and neutralizing the resulting carbonate with hydrochloric acid, the name "spirit of hartshorn" was applied to ammonia.[7][8]

Gaseous ammonia was first isolated by Joseph Priestley in 1774 and was termed by him "alkaline air".[9] Eleven years later in 1785, Claude Louis Berthollet ascertained its composition.[7]

The Haber-Bosch process to produce ammonia from the nitrogen in the air was developed by Fritz Haber and Carl Bosch in 1909 and patented in 1910. It was first used on an industrial scale by the Germans during World War I,[1] following the allied blockade that cut off the supply of nitrates from Chile. The ammonia was used to produce explosives to sustain their war effort.[10]

Prior to the availability of cheap natural gas, hydrogen as a precursor to ammonia production was produced via the electrolysis of water or using the chloralkali process.

參考[編輯]

  1. 1.0 1.1 Max Appl (2006). Ammonia, in Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_143.pub2. 
  2. ammonia is a purple gas.Kirschbaum, B; Sica, D; Anderson, Fp (1999). "Urine electrolytes and the urine anion and osmolar gaps.". The Journal of laboratory and clinical medicine. 133 (6): 597–604. ISSN 0022-2143. PMID 10360635. doi:10.1016/S0022-2143(99)90190-7. 
  3. "Ammonia". h2g2 Eponyms. BBC.CO.UK. 11 January 2003. 原先內容歸檔睇2 November 2007. 喺8 November 2007搵到. 
  4. Chisholm 1911 cites Pliny Nat. Hist. xxxi. 39
  5. "Sal-ammoniac". Webmineral. 喺7 July 2009搵到. 
  6. Haq, Syed Nomanul (28 February 1995). Names, Natures and Things: The Alchemist Jabir Ibn Hayyan and His Kitab Al-Ahjar (Book of Stones). Springer. ISBN 978-0-7923-3254-1. 喺22 June 2010搵到. 
  7. 7.0 7.1 7.2 Chisholm 1911.
  8. Maurice P. Crosland (2004). Historical Studies in the Language of Chemistry. Courier Dover Publications. 第 72頁. ISBN 0-486-43802-3. 
  9. Abraham, Lyndy (1990). Marvell and alchemy. Aldershot Scolar. ISBN 0-85967-774-5. 
  10. Smith, Roland (2001). Conquering Chemistry. Sydney: McGraw-Hill. ISBN 0-07-470146-0.