化學專業英語常用句型例談

　　摘 要： 分解反應、歧化反應、中和反應、還原反應、氧化反應是無機化學中重要的反應，本文分析了發生這些反應的無機物，并列舉了它們發生反應及反應條件的英文句型表達方式，希望對化學專業英語教學提供一些參考和借鑒作用。
　　關鍵詞： 化學專業 常用句型 英語教學
　　
　　化學專業英語是查閱和閱讀化學外文文獻和撰寫外文資料的重要的基礎課程，該門課程的教學不僅涵蓋了化學各學科的專業詞匯和化學術語的教學上，更重要的方面還包括化學專業英語常用句型，具體的是化學性質、結構、反應、制備、用途等表達方式的教學上。如何才能完整準確地表達化學專業英語，上好雙語課程和寫出規范的化學英文論文，探討化合物在性質、反應、結構、制備、用途上的常用句型和搭配方式規律是很重要的。本文從無機化合物典型的化學反應來探討化學專業英語常用句型表達方式。
　　一、分解反應句型
　　在無機化合物中碳酸氫鹽、氯酸鹽、硝酸鹽、過氧化氫、碳酸等易于分解，這些化合物分解常需加熱或催化劑，表示它們分解反應的詞為decompose或decomposition，常用句型如下：
　　（1）When water containing HCO is heated，the bicarbonate ion rapidly decomposes to give carbonate，carbon dioxide，and water.
　　（2）When compounds containing nitrates are heated，they do not readily release all of the oxygenatoms in the compound.They decompose to give a compound that is a nitrite along with oxygen gas.
　　（3）When compounds containing chlorates are heated，they decompose to give the metal chloride and oxygen gas.
　　（4）Hydrogen peroxide undergoes decomposition in the presence of catalyst to produce oxygen gas and water.The iodide ion or MnO2 catalyzes this reaction.
　　（5）Carbonic acid is a very unstable substance and decomposes to give carbon dioxide and water.
　　經常對具有分解反應的無機物加以綜合，不僅有助于專業英語的學習，也有助于無機化學的學習。另外，某些金屬碳酸鹽、氫氧化物等也可發生分解反應。
　　二、歧化反應
　　歧化反應也是無機化學中的重要反應，三價猛和錳酸鹽在溶液中會發生歧化反應，氯和溴在堿性介質中也易歧化，氧化亞銅在稀硫酸酸性條件下岐化為二價銅和金屬銅。掌握一些無機物的歧化反應結合化合物的名稱和兩個英語詞匯disproportionation和disproportionate可以用專業英語很好地描述該反應。
　　（1）Mn3+ is unstable；its disproportionation is spontaneous.
　　（2）Manganate ion is also instable in unstable in acidic solution；its disproportionation gives permanganate and manganese（II）ion.
　　（3）In the sodium carbonate solutions，bromine disproportionates to form sodium bromide and sodium bromate.
　　（4）Chlorate salts form when Cl2 disproportionates in hot alkaline solutions.Hypochlorites form in cold alkaline solutions.
　　三、中和反應
　　在無機反應中，酸堿中和形成鹽發生中和反應，常用的詞匯有名詞neutralization和動詞neutralize。它們在句子中的位置及描述該反應的句型如下：
　　（1）CaCl2 is a salt formed during the neutralization reaction of hydrochloric acid with calcium hydroxide.
　　（2）A salt and water are formed when sulfuric acid neutralizes sodium hydroxide.
　　（3）A neutralization reaction involves the combination of hydrogen ions and hydroxide ions to form water.
　　（4）Ammonia undergoes neutralization reaction with hydrochloric acid to form ammonium chloride.
　　四、還原反應句型
　　金屬的制備或冶煉等常用還原法，reduction和reduce可用于描寫還原反應。典型的例句如下：
　　（1）After purification，the tin（IV） oxide is reduced with carbon to produce tin metal.
　　（2）Calcium，strontium，and barium are obtained by the reduction of their oxides with aluminum.
　　（3）Tin（II）chloride is a good reducing agent and is used in the quantitative analysis iron ores to reduce Fe（III）to Fe （II）in aqueous solution.
　　（4）Pb（IV）compounds tend to undergo reduction to compounds of Pb（II）and therefore good oxidizing agents.
　　（5）Chromium（II）compounds can be prepared by the reduction of Cr（III）compounds with zinc in acidic solution.
　　（6）Pure Cr can be obtained in small amounts by reducing Cr2O3 with Al in a reaction similar to the thermite reaction.
　　五、氧化反應句型
　　硝酸、濃硫酸、高錳酸鉀、重鉻酸鉀等都是強氧化劑，有關它們的反應涉及氧化反應，常見氧化反應句型如下：
　　
　　（1）Both Cu and Ag react with concentrated H2SO4 or HNO3.The metals are oxidized to Cu2+ and Ag+，respectively，and the reduction products are SO2 and NO.
　　（2）The HNO3 oxidizes the metal and Cl- from the HCl promotes the formation of the stable complex ion［AuCl4］-.
　　（3）Concentrated H2SO4 is a sufficiently strong oxidizing agent to oxidize Br- to Br2 and I- to I2.
　　（4）Then sulfur trioxide is produced by oxidizing SO2 in an exothermic，reversible reaction.
　　（5）Sulfites are good reducing agents and easily oxidized by O2.
　　（6）Ammonia and CuO can Undergo oxidation-reduction to form nitrogen.
　　（7）When copper reacts with dilute nitric acid，Copper is oxidized to copper（II） nitrate，and nitric acid is reduced to nitrogen monoxide.
　　（8）Firstly，ammonia is converted to NO by oxidation in the presence of platinum，followed by reaction with air and then water to yield nitric acid.
　　六、化合物電離
　　酸、堿、鹽在水中電離出氫離子、氫氧根離子、正離子或陰離子。它們與化學反應不同，沒有形成新的物質，只是離解出離子，可以用ionize和dissociate來描述。
　　（1）When ammonia dissolves in water，the aqueous solution partially ionize into ammonium ions and hydroxide ions.
　　（2）Nitric acid is a strong acid，it is completely ionized to hydrogen ion and nitrate ion.
　　（3）Water very slightly ionize to hydronium and hydroxide ions.
　　（4）Hydrogen sulfate ions dissociate in water into hydrogen ion and sulfate.
　　（5）Hydrosulfuric acid is a weak acid，it can partly ionize to hydrogen sulfide ion.
　　（6）Sulfuric acid is a strong diprotic acid and it almost completely ionize in water to hydrogen sulfate ion in the first step.
　　
　　參考文獻：
　　［１］Ralph H.Petrucci等.普通化學原理與應用（第八版影印版）.高等教育出版社.
　　［2］Michael Lewis.化學專業英語基礎（圖示教程）.上海外語教育出版社.