应用化学专业英语翻译.doc

10级应用化学（2）班郑禄春B2010063224

Lessen24ChemicalReactions
Conservationofmassandenergy（质量与能量守恒）
Twoconservationlaws（定律）applytoallchemicalreactions:Energycanneitherbecreatednordestroyed,andmattercanneitherbecreatednordestroyed.Thustheatomstakingpartinachemicalreactionmayberearranged,butalltheatomspresentinthereactantsmustalsobepresentintheproducts,andthetotalmassofthereactantsmustequalthetotalmassoftheproducts.
化学反应
质量守恒和能量守恒
两个守恒定律(定律)适用于所有的化学反应:能量既不能创造也不能消灭,物质也不能创造也不能消灭。因此原子参与化学反应可能重新安排,但所有的原子出现在反应物必须包含在产品,反应物的总质量必须等于生产物的总质量。
Whatisachemicalreaction?
Achemicalreactionoccurswhensubstances(thereactants)collide(碰撞)withenoughenergytorearrangetoformdifferentcompounds(theproducts).Thechangeinenergythatoccurswhenareactiontakeplaceisdescribedbythermodynamics(热力学）andtherateorspeedatwhichareactionoccursisdescribedbykinetics(动力学).Reactionsinwhichthereactantsandproductscoexistareconsideredtobeinequilibrium(处于平衡).Achemicalequationconsistsofthechemicalformula（化学式）ofthereactants,andthechemicalformulaoftheproducts.Thetwoareseparatedbyan→usuallyreadas“yields”andeachchemicalformulaisseparatedfromothersbyaplussign(加号).Sometimesatriangleisdrawnoverthearrowsymboltodenoteenergymustbeaddedtothesubstancesforthereactiontobegin.Eachchemicalformulamaybeprecededbyascalar(数量的)coefficientindicatingtheproportion(比例)ofthatsubstancenecessarytoproducethereactioninformula.Forinstance,theformulafortheburningofmethane(CH4+2O2→CO2+2H2O)indicatesthattwiceasmuchO2asCH4isneeded,andwhentheyreact,twiceasmuchH2OasCO2willbeproduced.Thisisbecauseduringthereaction,eachatomofcarbonneedsexactlytwoatomsofoxygentocombinewith,toproducetheCO2,andeverytwoatomsofhydrogenneedanatomofoxygentocombinewithtoproducetheH2O.Iftheproportionsofthereactantsarenotrespected,whentheyareforcedtoreact,eithernotallofthesubstanceusedwillparticipateinthereaction,orthereactionthatwilltakeplacewillbedifferentfromtheonenotedintheequation..
什么是化学反应
一个化学反应发生在物质(反应物)碰撞有足够的能量去重新排列,形成不同的化合物(产品)。当反应发生时能量发生变化由热力学描述，利率或速度进行反应发生是由动力学描述。反应中,反应物和生成物共存被认为是处于