2024年化学专业英语修订版翻译

01THEELEMENTSANDTHEPERIODICTABLE01元素和元素周期表Thenumberofprotonsinthenucleusofanatomisreferredtoastheatomicnumber,orprotonnumber,Z.Thenumberofelectronsinanelectricallyneutralatomisalsoequaltotheatomicnumber,Z.Thetotalmassofanatomisdeterminedverynearlybythetotalnumberofprotonsandneutronsinitsnucleus.Thistotaliscalledthemassnumber,A.Thenumberofneutronsinanatom,theneutronnumber,isgivenbythequantityA-Z.在壹种原子核中的质子数量被称為原子序数，或质子数，Z。在壹种電中性原子中的電子数量也等于原子序数，Z。壹种原子的總质量被测定是非常靠近于原子核中质子和中子的總数。這個總数被称為质量数，A。在壹种原子中的中子数量等于A–Z的数量。Thetermelementrefersto,apuresubstancewithatomsallofasinglekind.Tothechemistthe"kind"ofatomisspecifiedbyitsatomicnumber,sincethisisthepropertythatdeterminesitschemicalbehavior.AtpresentalltheatomsfromZ=1toZ=107areknown;thereare107chemicalelements.Eachchemicalelementhasbeengivenanameandadistinctivesymbol.FormostelementsthesymbolissimplytheabbreviatedformoftheEnglishnameconsistingofoneortwoletters,forexample:這個术語(指chemicalelement)也可以指由相似质子数的原子构成的纯化學物质。對化學家来說，此类原子通過原子数来阐明，由于它的性质是决定其化學行為。目前，從Z=1到Z=107的所有原子是懂得的；有107种化學元素。每壹种化學元素起了壹种名字和独特的象征。對于大多数元素都仅仅是壹种象征的英文名称缩写形式，由壹种或两個字母构成，例如：oxygen==Onitrogen==Nneon==Nemagnesium==Mg氧==O氮==N氖==Ne镁==MgSomeelements,whichhavebeenknownforalongtime,havesymbolsbasedontheirLatinnames,forexample:很久以来就已經懂得某些元素，根据他們的拉丁名字符号命名，例如：iron==Fe(ferrum)copper==Cu(cuprum)lead==Pb(plumbum)铁==铁(铁)铜==铜(铜)铅==铅(铅)AcompletelistingoftheelementsmaybefoundinTable1.壹种完整的元素可以在表1中被发現。BeginninginthelateseventeenthcenturywiththeworkofRobertBoyle,whoproposedthepresentlyacceptedconceptofanelement,numerousinvestigationsproducedaconsiderableknowledgeofthepropertiesofelementsandtheircompounds1.In1869,D.MendeleevandL.Meyer,workingindependently,proposedtheperiodiclaw.Inmodernform,thelawstatesthatthepropertiesoftheelementsareperiodicfunctionsoftheiratomicnumbers.Inotherwords,whentheelementsarelistedinorderofincreasingatomicnumber,elementshavingcloselysimilarpropertieswillfallatdefiniteintervalsalongthelist.Thusitispossibletoarrangethelistofelementsintabularformwithelementshavingsimilarpropertiesplacedinverticalcolumns2.Suchanarrangementiscalledaperiodic.早在拾七世纪末期，罗伯特波义耳就開始了這项工作，他提出了目前公认的元素的概念，大量的研究使我們對元素及其化合物的性质有了相称的理解。在1869年，门捷列夫和迈耶，独立工作，提出了元素周期律。用現代方式，元素周期律论述了元素的特性原子序数的周期性函数。换句话說，當按原子序数增長的次序排列元素，具有相近特性的元素将沿著列表以壹定的间隔下降。因此，将具有类似性质的元素排成纵列，從而把元素排成表格形式是有也許的。像這样的排列叫元素周期表。Eachhorizontalrowofelementsconstitutesaperiod.Itshouldbenotedthatthelengthsoftheperiodsvary.Thereisaveryshortperiodcontainingonly2elements,followedbytwoshortperiodsof8elementseach,andthentwolongperiodsof18elementseach.Thenextperiodincludes32elements,andthelastperiodisapparentlyincomplete.Withthisarrangement,elementsinthesameverticalcolumnhavesimilarcharacteristics.Thesecolumnsconstitutethechemicalfamiliesorgroups.Thegroupsheadedbythemembersofthetwo8-elementperiodsaredesignatedasmaingroupelements,andthemembersoftheothergroupsarecalledtransitionorinnertransitionelements.每個水平排的元素构成壹种周期。但应當注意的是，周期長度會发生变化。非常短的周期只包括二元素，背面跟著两個8個元素短周期，然後是两個由18個元素构成的長周期。下壹种周期包括32個元素，最终壹种周期明显是不完整的。按照這样的安排，在同壹垂直栏的元素有相似的特點。這些垂直栏构成化學族。两個8個元素的周期构成的元素被认為是主族元素，其他族的元素被称為過渡元素。Intheperiodictable,aheavysteppedlinedividestheelementsintometalsandnonmetals.Elementstotheleftofthisline(withtheexceptionofhydrogen)aremetals,whilethosetotherightarenonmetals.Thisdivisionisforconvenienceonly;elementsborderingtheline—themetalloids-havepropertiescharacteristicof-bothmetalsandnonmetals.Itmaybeseenthatmostoftheelements,includingallthetransitionandinnertransitionelements,aremetals.在元素周期表，阶梯线将元素提成金属和非金属元素等。阶梯线左边的元素(除氢)是金属，右边的是非金属元素等。這個分割仅為以便使用；元素分界线上的元素—准金属具有金属和非金属的特性。這可以看出，大部分的元素，包括所有的過渡和内在過渡元素，是金属。Exceptforhydrogen,agas,theelementsofgroupIAmakeupthealkalimetalfamily.Theyareveryreactivemetals,andtheyareneverfoundintheelementalstateinnature.However,theircompoundsarewidespread.Allthemembersofthealkalimetalfamily,formionshavingachargeof1+only.Incontrast,theelementsofgroupIB—copper,silver,andgold—arecomparativelyinert.Theyaresimilartothealkalimetalsinthattheyexistas1+ionsinmanyoftheircompounds.However,asischaracteristicofmosttransitionelements,theyformionshavingotherchargesaswell.除了氢气，IA由碱金属元素构成。他們是非常活泼的金属，在自然界中，它們從没有以元素态形式出現。然而，他們的化合物是广泛存在的。所有的碱金属离子仅有1+的電荷。相比之下，IB铜，银和金是惰性的。在他們的許多化合物他們存在1+离子，這与碱金属离子是相似的。然而，像許多過渡元素所具有的特點同样，他們也形成具有其他電荷的离子。TheelementsofgroupIIAareknownasthealkalineearthmetals.Theircharacteristicionicchargeis2+.Thesemetals,particularlythelasttwomembersofthegroup,arealmostasreactiveasthealkalimetals.ThegroupIIBelements—zinc,cadmium,andmercuryarelessreactivethanarethoseofgroupIIA5,butaremorereactivethantheneighboringelementsofgroupIB.Thecharacteristicchargeontheirionsisalso2+.IIA的元素被称為碱土金属。其特點是离子電荷2+。這些金属，尤其是最终两個元素，几乎具有与碱金属同样的反应活性。IIB元素，锌，镉，汞比IIA的元素具有更少的反应活性，不過比相邻的IB的元素有更强的反应活性。IB的元素离子的特性電荷也是2+。Withtheexceptionofboron,groupIIIAelementsarealsofairlyreactivemetals.Aluminumappearstobeinerttowardreactionwithair,butthisbehaviorstemsfromthefactthatthemetalformsathin,invisiblefilmofaluminumoxideonthesurface,whichprotectsthebulkofthemetalfromfurtheroxidation.ThemetalsofgroupIIIAformionsof3+charge.GroupIIIBconsistsofthemetalsscandium,yttrium,lanthanum,andactinium.除了硼、IIIA元素也是具有相称强活性金属。在空气中铝似乎惰性的，但這种行為的本源是金属表面形成了壹层薄的、不可見的氧化铝膜，這层膜保护大量的金属的深入氧化。IIIA金属离子具有3+的電荷。IIIA由金属钪，钇，镧系和锕系元素构成。GroupIVAconsistsofanonmetal,carbon,twometalloids,siliconandgermanium,andtwometals,tinandlead.EachoftheseelementsformssomecompoundswithformulaswhichindicatethatfourotheratomsarepresentpergroupIVAatom,as,forexample,carbontetrachloride,CCl4.ThegroupIVBmetals—titanium,zirconium,andhafnium—alsoformscompoundsinwhicheachgroupIVBatomiscombinedwithfourotheratoms;thesecompoundsarenonelectrolyteswhenpure.IVA元素由壹种非金属，碳、两個准金属，硅和锗，和两個金属，锡和铅构成。按照配位规则，這些元素的每壹种形成某些化學物，這表明每壹种IVA原子需要四個其他原子配位，例如，四氯化碳CCl4。IVB金属—钛、锆、和铪—也形成化合物，其中每個IVB原子結合四個其他原子；這些化合物的纯物质是非電解质。TheelementsofgroupVAincludethreenonmetals—nitrogen,phosphorus,andarsenic—andtwometals—antimonyandbismuth.AlthoughcompoundswiththeformulasN2O5,PCl5,andAsCl5exist,noneofthemisionic.Theseelementsdoformcompounds-nitrides,phosphides,andarsenides—inwhichionshavingchargesofminusthreeoccur.TheelementsofgroupVBareallmetals.Theseelementsformsuchavarietyofdifferentcompoundsthattheircharacteristicsarenoteasilygeneralized.VA元素包括三种非金属--氮、磷、砷，和两种金属锑和铋。尽管物质N2O5，PCl5，AsCl5存在，不過其中没有壹种是离子。這些元素能形成化合物—氮化物，磷化物，和砷化物—其中离子带3-价的负電荷。VB的元素都是金属。這些元素形成多种不壹样的化合物，它們的特性不轻易归纳。Withtheexceptionofpolonium,theelementsofgroupVIAaretypicalnonmetals.Theyaresometimesknown,asthe,chalcogens,fromtheGreekwordmeaning"ashformers".Intheirbinarycompoundswithmetalstheyexistasionshavingachargeof2-.TheelementsofgroupⅦAareallnonmetalsandareknownasthehalogens.fromtheGreektermmeaning"saltformers.”Theyarethemostreactivenonmetalsandarecapableofreactingwithpracticallyallthemetalsandwithmostnonmetals,includingeachother.除了钋的元素，VIA族元素是經典的非金属。他們是众所周知的硫族元素，這来自于希腊字母，詞意是“灰的发明者”。在他們与金属离子形成的二元化合物中离子带2-价的電荷。ⅦA族的元素都是非金属，被称為卤素，来自希腊术語，意即“盐的发明者”。他們是最具有反应活性的非金属，可以与所有的金属和大多数非金属反应，包括互相之间的反应。TheelementsofgroupsⅥB,ⅦB,andVIIIBareallmetals.TheyformsuchawideVarietyofcompoundsthatitisnotpracticalatthispointtopresentanyexamplesasbeingtypicalofthebehavioroftherespectivegroups.ⅥB，ⅦB，和VIIIB族元素都是金属。它們形成了多种各样的化合物，在這壹點上我們甚至不能举出任何能体現各族元素經典变化的例子。Theperiodicityofchemicalbehaviorisillustratedbythefactthat，excludingthefirstperiod,eachperiodbeginswithaveryreactivemetal.Successiveelementalongtheperiodshowdecreasingmetalliccharacter,eventuallybecomingnonmetals,andfinally,ingroupⅦA,averyreactivenonmetalisfound.Eachperiodendswithamemberofthenoblegasfamily.除了第壹种周期，化學行為的周期性可以用事实阐明，每壹种周期以壹种非常活泼的金属開始。沿著周期元素显示出了逐渐減少的金属性，最终成為非金属，最终，在ⅦA族，可以发現壹种很活泼的非金属元素。每壹种周期的結尾是壹种稀有气体元素。02THENONMETALELEMENTS02非金属元素Wenotedearlierthat-nonmetalsexhibitpropertiesthataregreatlydifferentfromthoseofthemetals.Asarule,thenonmetalsarepoorconductorsofelectricity(graphiticcarbonisanexception)andheat;theyarebrittle,areoftenintenselycolored,andshowanunusuallywiderangeofmeltingandboilingpoints.Theirmolecularstructures,usuallyinvolvingordinarycovalentbonds,varyfromthesimplediatomicmoleculesofH2,Cl2,I2,andN2tothegiantmoleculesofdiamond,siliconandboron.很早我們就已經注意到非金属体現出了与金属不壹样样的特性。壹般来說，非金属是比较差的電子（石墨碳除外）和热的导体；他們是易碎的，壹般具有较强的颜色，并体現出很宽范围的熔點和沸點。他們的分子构造，壹般是包括了壹般的共价键，從简朴的双原子分子的H2，Cl2，I2和N2到钻石、硅和硼的大分子。Thenonmetalsthataregasesatroomtemperaturearethelow-molecularweightdiatomicmoleculesandthenoblegasesthatexertverysmallintermolecularforces.Asthemolecularweightincreases,weencounteraliquid(Br2)andasolid(I2)whosevaporpressuresalsoindicatesmallintermolecularforces.CertainpropertiesofafewnonmetalsarelistedinTable2.在室温下是气相的非金属是低分子质量的双原子分子和施加了非常小的分子间作用力的稀有气体。伴随分子量的增大，我們碰到了壹种液体(Br2)和壹种固体(I2)，其蒸气压也表明小的分子间作用力。某些非金属的某些性质列在表2中。Table2MolecularWeightsandMeltingPointsofCertainNonmetalsDiatomicMoleculesMolecularWeightMeltingPoint°CColorH22-239.1'NoneN228-210NoneF238-223PaleyellowO232-218PaleblueCl271-102Yellow—greenBr2160-7.3Red—brownI2254113Gray—blackSimplediatomicmoleculesarenotformedbytheheaviermembersofGroupsVandVIatordinaryconditions.Thisisindirectcontrasttothefirstmembersofthesegroups,N2andO2.Thedifferencearisesbecauseofthelowerstabilityofπbondsformedfromporbitalsofthethirdandhighermainenergylevelsasopposedtothesecondmainenergylevel2.Thelargeratomicradiiandmoredenseelectroncloudsofelementsofthethirdperiodandhigherdonotallowgoodparalleloverlapofporbitalsnecessaryforastrongπbond.Thisisageneralphenomenon—strongπbondsareformedonlybetweenelementsofthesecondperiod.Thus,elementalnitrogenandoxygenformstablemoleculeswithbothσandπbonds,butothermembersoftheirgroupsformmorestablestructuresbasedonσbondsonlyatordinaryconditions.Note3thatGroupVIIelementsformdiatomicmolecules,butπbondsarenotrequiredforsaturationofvalence.壹般状况下，V和VI族包括的更重的元素不能形成简朴的双原子分子。這与這两個族中所包括的第壹种元素是直接相反的，N2和O2。差异的出現是由于与第二主能级相反，第三和更高主能级的p轨道形成的π键稳定性较低。第三和更高周期元素的更大的原子半径和更密的電子雲不容許壹种强的π键所必需的p轨道很好的平行重叠。這是壹种普遍的現象—强的π键仅仅在第二周期的元素之间形成。因此，氮和氧元素形成了具有σ和π键的稳定分子，不過在壹般状况下，這两個族的其他元素可以形成仅仅基于σ键的更稳定的构造。需要注意的是第VII族元素形成了双原子分子，不過π键不需要用于价态的饱和。Sulfurexhibitsallotropicforms.Solidsulfurexistsintwocrystallineformsandinanamorphousform.Rhombicsulfurisobtainedbycrystallizationfromasuitablesolution,suchasCS2,anditmeltsat112°C.Monoclinicsulfurisformedbycoolingmeltedsulfuranditmeltsat119°C.BothformsofcrystallinesulfurmeltintoS-gamma,whichiscomposedofS8molecules.TheS8moleculesarepuckeredringsandsurviveheatingtoabout160°C.Above160°C,theS8ringsbreakopen,andsomeofthesefragmentscombinewitheachothertoformahighlyviscousmixtureofirregularlyshapedcoils.Atarangeofhighertemperaturestheliquidsulfurbecomessoviscousthatitwillnotpourfromitscontainer.Thecoloralsochangesfromstrawyellowatsulfur'smeltingpointtoadeepreddish-brownasitbecomesmoreviscous.硫具有同素异形体。固态硫存在两种晶形和壹种無定形的形式。斜方硫通過在合适的溶液中結晶化获得，如CS2，在112°C時融化。單斜硫通過冷却融化的硫获得和單斜硫在119°C時融化。两种形式的晶体硫融化成S-gamma，它由S8分子构成。S8的分子起皱成环和加热到160°C仍然存在。超過160°C，S8环被破壞，其中的某些片段互相結合形成壹种高粘度的形状不规则的混合物。在更高的温度范围液态硫变得黏度很高，以致于在容器中不能倒出。伴随变得更粘稠，其颜色也從硫熔點時的稻草黄色变成紅褐色。As4theboilingpointof444°Cisapproached,thelarge-coiledmoleculesofsulfurarepartiallydegradedandtheliquidsulfurdecreasesinviscosity.Ifthehotliquidsulfurisquenchedbypouringitintocoldwater,theamorphousformofsulfurisproduced.Thestructureofamorphoussulfurconsistsoflarge-coiledheliceswitheightsulfuratomstoeachturnofthehelix;theoverallnatureofamorphoussulfurisdescribedas3rubberybecauseitstretchesmuchlikeordinaryrubber.Inafewhourstheamorphoussulfurrevertstosmallrhombiccrystalsanditsrubberypropertydisappears.伴随靠近444°C的沸點，硫的大的螺旋状分子被部分降解和液态硫的黏度減少。假如把热的液态硫倒入到冷却水裏骤冷，就會产生無定形硫。無定形硫的构造由具有8個硫原子的大的螺旋线构成；無定形硫的總特性被描述成是有弹性的，由于它可以类似于壹般的橡胶伸张。几种小時之内無定形硫恢复成菱形晶体，和它的弹性性质消失。Sulfur,animportantrawmaterialinindustrialchemistry,occursasthefreeelement,asSO2involcanicregions,asH2Sinmineralwaters,andinavarietyofsulfideoressuchasironpyriteFeS2,zincblendeZnS,galenaPbSandsuch,andincommonformationsofgypsumCaSO4•2H2O,anhydriteCaSO4,andbarytesBaSO4•2H2O.Sulfur,inoneformoranother,isusedinlargequantitiesformakingsulfuricacid,fertilizers,insecticides,andpaper.硫在工业化學中是壹种重要的原材料，它以單质，在火山区域以SO2，在矿泉水中H2S，和多种硫化物出現，像黄铁矿FeS2，闪锌矿ZnS，方铅矿PbS等等，尚有石膏CaSO4•2H2O，硬石膏CaSO4，以及重晶石BaSO4•2H2O等壹般形态。硫或以某种方式，用于大量制造硫酸、肥料、杀虫剂、和紙张。SulfurintheformofSO2obtainedintheroastingofsulfideoresisrecoveredandconvertedtosulfuricacid,althoughinpreviousyearsmuchofthisSO2wasdiscardedthroughexceptionallytallsmokestacks.Fortunately,itisnoweconomicallyfavorabletorecoverthesegases,thusgreatlyreducingthistypeofatmosphericpollution.Atypicalroastingreactioninvolvesthechange:2ZnS+3O2—2ZnO+2SO2在硫化物煅烧中获得的以SO2形式存在的硫被转化成硫酸，尽管在過去几年許多二氧化硫通過高烟囱排放出去。幸运的是，目前回收這些气体的成本是较低的，從而這可以大幅度地減少大气污染。經典的焙烧反应如下：2ZnS+3O2-2氧化锌+2二氧化硫Phosphorus,below800℃consistsoftetratomicmolecules,P4.Itsmolecularstructureprovidesforacovalenceofthree,asmaybeexpectedfromthethreeunpairedpelectronsinitsatomicstructure,andeachatomisattachedtothreeothers6.Insteadofastrictlyorthogonalorientation,withthethreebonds90°toeachother,thebondanglesareonly60°.Thissupposedlystrainedstructureisstabilizedbythemutualinteractionofthefouratoms(eachatomisbondedtotheotherthree),butitischemicallythemostactiveformofphosphorus.Thisformofphosphorus,thewhitemodification,isspontaneouslycombustibleinair.Whenheatedto260°Citchangestoredphosphorus,whosestructureisobscure.Redphosphorusisstableinairbut,likeallformsofphosphorus,itshouldbehandledcarefullybecauseofitstendencytomigratetotheboneswheningested,resultinginseriousphysiologicaldamage.在低于800℃時，磷由四原子分子构成，P4。它的分子构造提供了三個共价，可预期三個共价是由该原子构造中三個未成對的p電子形成的，且每個原子都与此外三個相接。不是严格的正交取向，即三個键互成90°，而是键角仅仅是60°。這种也許的收缩构造通過4個原子的互相作用来稳定（每壹种原子与其他三個原子成键），不過它是化學上最活跃的磷的形式。這种形式的磷、白磷，在空气中能自发燃烧。當加热到260°C時，它转变成紅磷，其构造是不确定的。紅色是在空气中是稳定的，不過，就像所有形式的磷，它应當谨慎处理，由于當摄取時，它倾向于迁移到骨頭，這會导致严重的生理伤害。Elementalcarbonexistsinoneoftwocrystallinestructures—diamondandgraphite.Thediamondstructure,basedontetrahedralbondingofhybridizedsp3orbitals,isencounteredamongGroupIVelements.Wemayexpectthatasthebondlengthincreases,thehardnessofthediamond-typecrystaldecreases.Althoughthetetrahedralstructurepersistsamongtheelementsinthisgroup—carbon,silicon,germanium,andgraytin—theinteratomicdistancesincreasefrom1.54Aforcarbonto2.80Aforgraytin.Consequently,thebondstrengthsamongthefourelementsrangefromverystrongtoquiteweak.Infact,graytinissosoftthatitexistsintheformofmicrocrystalsormerelyasapowder.TypicaloftheGroupIVdiamond-typecrystallineelements,itisanonconductorandshowsothernonmetallicproperties7.碳元素存在两种晶体构造——金刚石和石墨。基于杂化的sp3轨道四面体成键的金刚石构造碰到第IV族元素。我們也許但愿键長增長，金刚石类型的晶体硬度減少。虽然四面体构造的元素存在這個族-碳、硅、锗，和灰锡-原子间的距离由碳的1.54Å增長到灰锡的2.80Å。因此，在這四個元素之间，键的强度由强变弱。实际上，灰锡是非常柔软的，以致于它以微晶或粉末形式存在。碳作為經典的第IV族金刚石型晶体的元素，它是不良导体，且显示其他非金属性质。10ALKANES10烷烃NumberofIsomers同分异构体的数量Thecompoundsnowassignedthegenericnamealkanearealsoreferredtoassaturatedhydrocarbonsandasparaffinhydrocarbons.Thewordparaffin,fromtheLatinparumaffinis(slightaffinity)referstotheinertchemicalnatureofthesubstancesandisappliedalsotothewaxobtainablefrompetroleumandconsistingofamixtureofhigheralkanes.目前指定属名為烷烃的化合物也被叫做饱和烷烃和链烷烃。石蜡壹詞,来自拉丁語“parumaffinis”(很少亲和性的),指的是化學惰性的物质,并也合用于從石油和高级烷烃混合物中的得到的蜡。Derivationoftheformulasofthepentanes(3isomers),hexanes(5).andheptanes(9)hasalreadydemonstratedthesharpriseindiversitywithincreasingcarboncontent.戊烷（3個同分异构体），已烷（5個同分异构体），和庚烷（9個同分异构体）的衍生物已經表明了伴随C含量增長，衍生物的数量會大幅度的上升。NormalAlkanes正烷烃SuccessivemembersoftheseriesdifferincompositionbytheincrementCH2andformahomologousseries.Thusheptaneandoctanearehomologoushydrocarbons;icosaneisahigherhomologofmethane.這壹系列中接连相邻的组员间构成不壹样，通過增長CH2形成同系物。因此，庚烷和辛烷是同系碳氢化合物；二拾烷是甲烷的壹种较高的同系物。SaturatedUnbranched—ChainCompoundsandUnivalentRadicals饱和無支链的链状化合物和單价基团Thefirstfoursaturatedunbranchedacyclichydrocarbonsarecalledmethane,ethane,propaneandbutane.Namesofthehighermembersofthisseriesconsistofanumericalterm,followedby"-ane"withelisionofterminal"a"fromthenumericalterm.Examplesofthesenamesareshowninthetablebelow.Thegenericnameof-saturatedacyclichydrocarbons(branchedorunbranched)is“alkane.”前四個饱和無支链的非环状碳氢化合物被称為甲烷，乙烷，丙烷和丁烷。這壹系列中更高的组员的命名包括壹种数字项，紧接著是-ane，其中数字项結尾省略了a。這些名称的例子如下表所示。（含支链或非支链）的饱和無环碳氢化合物通用都被称作“烷烃”。Examplesofnames:(n=totalnumberofcarbonatoms)实例名称：(n=碳原子的總数)nnn1Methane甲烷15Pentadecane拾五烷29Nonacosane二拾九烷2Ethane乙烷16Hexadecane拾六烷30Triacontane三拾烷3Propane丙烷17Heptadecane拾七烷31Hentriacontane三拾壹烷4Butane丁烷18Octadecane拾八烷32Dotriacontane三拾二烷5Pentane戊烷19Nonadecane拾九烷33Tritriacontane三拾三烷6Hexane已烷20Icosane二拾烷40Tetracontane四拾烷7Heptane庚烷21Henicosane二拾壹烷50Pentacontane五拾烷8Octane辛烷22Docosane二拾二烷60Hexacontane六拾烷9Nonane壬烷23Tricosane二拾三烷70Heptacontane七拾烷10Decane癸烷24Tetracosane二拾四烷80Octacontane八拾烷11Undecane拾壹烷25Pentacosane二拾五烷90Nonacontane九拾烷12Dodecane拾二烷26Hexacosane二拾六烷100Hectane壹百烷13Tridecane拾三烷27Heptacosane二拾七烷132Dotriacontahectane132烷14Tetradecane拾四烷28Octacosane二拾八烷SaturatedbranchedacyclichydrocarbonisnamedbyprefixingthedesignationsofthesidechainstothenameofthelongestchainwhichisnumberedfromoneendtotheotherbyArabicnumerals,thedirectionbeingsochosenastogivethelowestnumberspossibletothesidechains.Whenseriesoflocantscontainingthesamenumberoftermsarecomparedtermbyterm,thatseriesis"lowest"whichcontainsthelowestnumberontheoccasionofthefirstdifference1.Thisprincipleisappliedirrespectiveofthenatureofthesubstituents.饱和的支链無环烃的命名是把侧链名称作為最長链名称的前缀，最長链用阿拉伯数字從壹端到另壹端進行编号，方向选择是為了让侧链的编号尽量低。當位次具有相似编号的系列被逐层比较時，直到出現第壹种不壹样，最低编号的那個体系就是最低的。這壹原则合用与不考虑取代基的种类。Thepresenceofidenticalunsubstitutedradicalsisindicatedbytheappropriatemultiplyingprefixdi-,tri-,tetra-,penta-,hexa-,hepta-,octa-,nona-,deca,etc.存在相似未取代基团通過合适增長前缀二，三，四，五，六，七，，八，九，拾等来表达。Univalentradicalsderivedfromsaturatedacyclichydrocarbonsbyremovalofhydrogenfromaterminalcarbonatomarenamedbyreplacingtheending"—ane"ofthenameofthehydrocarbonby"—yl".Thecarbonatomwiththefreevalenceisnumberedas1.Asaclass,theseradicalsarecallednormal,orunbranchedchain,alkyls.單价基团是從饱和無环烃中去掉端基碳原子上的氢得来，用－yl替代烷烃名字結尾中的－ane来命名。具有自由价的碳原子编号為1。作為壹类，這些基团被称為正烷基或非支链烷基。Stability.—Alkanesarerelativelyinert,chemically,sincetheyareindifferenttoreagentswhichreactreadilywithalkenesorwithalkynes.n-Hexane,forexample,isnotattackedbyconcentratedsulfuricacid,boilingnitricacid,molten"sodiumhydroxide,potassiumpermanganate,orchromicacid;withtheexceptionofsodiumhydroxide,thesereagentsallattackalkenesatroomtemperature.Thefewreactionsofwhichalkanesarecapablerequireahightemperatureorspecialcatalysis.稳定性。烷烃在化學上是相對惰性的，由于他們和与烯烃或炔烃反应的试剂不反应。例如，正已烷不与浓硫酸，沸腾的硝酸，熔融的氢氧化钠，高锰酸钾，或铬酸;除氢氧化钠，這些试剂都与烯烃在室温下反应。少数烷烃可以参与的反应规定较高的温度或特殊催化。Halogenation.—Ifatesttubecontainingn-hexaneisputinadarkplaceandtreatedwithadropofbromine,theoriginalcolorwillremainundiminishedinintensityfordays.Ifthesolutionisexposedtosunlight,thecolorfadesinafewminutes.andbreathingacrossthemouthofthetubeproducesacloudofcondensaterevealinghydrogenbromideasonereactionproduct.Thereactionisaphotochemicalsubstitution:卤化：假如把壹种装有正已烷的试管放在黑暗的地方加壹滴溴，本来的颜色将在强度上维持不退色好几天。假如溶液暴露在阳光下，颜色几分钟就消失了。试管口产生冷凝物，表明生成了HBr。這個反应光是化學取代反应：Chlorinationofalkanesismoregeneralandmoreusefulthanbrominationandcanbeeffectednotonlyphotochemicallybutalsobyothermethods.烷烃的氯化比烷烃的溴化更普遍和更有用，并且不仅可以通過光化學并且還可以通過其他措施实現。Lightinitiateschlorinationofanalkanebyconvertingchlorinemoleculesintochlorineatomsbyaprocessofhemolysis,inwhichacovalentbondisseveredandoneelectronisretainedbyeachoftheatomsformingthebond:Cl:Cl—→Cl•+C1•.Achlorineatomhasanodd,orunpairedelectronandisafreeradical.Becauseofthetendencyofatomstoattaintheirnormalvalenceshells,anyfreeradicalisahighlyreactivespecies.Photochemicalchlorinationproceedsthroughasuccessionoffreeradicals;itisafreeradicalchainreaction.Thechaininitiatingstep(1),hemolyticfissionofchlorinemolecules,produceschlorinefreeradicals;inchainpropagatingsteps,achlorineradicalattacksamoleculeofalkanetoproducehydrogenchlorideandanalkylradical(2),whichinturnattacksachlorinemoleculetoproduceachloroalkaneandachlorineradical(3).光引起烷烃的氯化通過均裂的形式将氯分子转化為氯原子。其中的共价键断了，每個本来形成键的原子分别保留壹种電子。壹种氯原子有壹种奇数的，或者未成對電子成為壹种游离基。由于原子倾向得到正常的价電子，任何游离基都是高活性的物种。光化學氯化通過游离基的传导实現，它是游离基的链反应。链引起环节（1），氯分子的均裂，产生了氯游离基;在链传播环节，壹种氯游离基袭击烷烃分子产生氯化氢和烷基游离基（2），而他又反過来袭击氯分子产生氯代烷烃和氯游离基（3）。Sincechlorine-radicalsrequiredinstep(2)areregeneratedinstep(3),thetworeactionstogetherconstituteachainwhich,ifbothreactionsproceededwithperfectefficiency,wouldbeself-propagatingwithoutfurtherrequirementoflightenergy,Theefficiency.however.isnotperfect,forchlorineradicalscanrecombine(4),combinewithalkylradicals(5),ordissipateenergybycollisionwiththeflaskwails.Hencecontinuedradiationisrequiredtomaintainanadequatesupplyofinitiatingradicals.Thechaininitiatingsteprequiresinputoflightenergyamountingto+242.8kJ/mole.Step(2),however,isexothermic,sincetheenergyrequiredtobreaktheC—HbondislessthanthebondenergyofH—Cl.Thesecondchainpropagatingstep(3)islikewiseexothermic,andindeedchlorinationofanalkanecanproceedexplosively.由于在环节（2）中需要的氯游离基在环节（3）中再生了，這两個反应共同构成链，假如两個反应均有较高的效率，反应将是自延续的，不再需要深入的光能。然而，效率并不非常好，氯游离基可以重组（4），并結合烷基（5），或通過与瓶壁碰撞来消耗能量。因此，需要继续辐射来维持提供充足的自由基。链引起环节需要投入光能达+242.8kJ/mole环节（2）然而，是放热的，由于所需的打破C-H键的能量少于H—Cl键的能量。第二個链传递环节（3）同样是放热，实际上烷烃的氯化可以爆炸式的发生。Cracking.—Heatedtotemperaturesintherange500~700°,higheralkanesundergopyrolyticruptureorcrackingtomixturesofsmallermolecules,somesaturatedandsomeunsaturated.Unsaturatedhydrocarbonsproducedbyselectivecrackingofspecificpetroleumfractionsareusefulinchemicalsynthesis.Crackingrupturescarbon—carbonratherthancarbon—hydrogenbondsbecausetheenergyrequiredtobreaktheC—Cbondis247kJ/mol,whereastheC—Hbondenergyis364kJ/mol.裂解：加热温度在500〜700℃范围内，高烷烃進行热解或裂解成為小分子的混合物，包括某些饱和不饱和的。通過选择性裂解特殊石油馏分得到的不饱和烃在化學合成上是非常有用的。裂解断裂的碳-碳键而不是碳氢键，由于打破C-C原子键所需的能量是247kJ/摩尔，而打破C-H键的能量是364kJ/mol。Oxidation.—Thereactionofhydrocarbonswithoxygenwiththeoutputofenergyisthebasisforuseofgasolineasfuelininternalcombustionengines.TheenergyreleaseonburningagivenhydrocarbonisexpressedastheheatofcombustionintermsofkJ/mole.氧化。碳氢化合物与氧反应放出能量是使用汽油作為内燃机燃料的基础。燃烧某壹特定的碳氢化合物所释放的能量用燃烧热来表达，單位是仟焦耳/摩尔。Incompletecombustionofgaseoushydrocarbonsisimportantinthemanufactureofcarbonblacks,particularlylampblack,apigmentforink,andchannelblack,usedasafillerinrubbercompounding.Naturalgasisusedbecauseofitscheapnessandavailability;theyieldofblackvarieswiththetypeofgasandthemanufacturingprocessbutusuallyisintherangeof2~6%ofthetheoreticalamount.气态烃的不完全燃烧在工业上生产炭黑上很重要，尤其是灯黑，壹种墨水颜料，和槽法炭黑，用作橡胶配方的填料。天然气的使用，由于其廉价和可实用性;黑的产率根据气体种类的不壹样以及制造工艺的不壹样而不壹样，但壹般是理论数额的2〜6％。Partialairoxidationofamorelimitedextentisameansforproductionofspecificoxygenatedsubstances.Controlledairoxidationofhigh-boilingmineraloilsandwaxesfrompetroleumaffordsmixturesofhighercarboxylicacidssimilartothosederivedfromfatsandsuitableforuseinmakingsoaps.空气部分氧化到壹定程度是生产特殊氧化物制的壹种手段，高沸點矿物油和石油中的蜡的可控空气氧化得到了类似于来自脂肪的高级羧酸混合物，合用于制作肥皂。24VOLUMETRICANALYSIS24容量分析Generalprinciples壹般原则Chemicalanalysescanbemadebydetermininghowmuchofasolutionofknownconcentrationisneededtoreactfullywithanunknowntestsample1.Themethodisgenerallyreferredtoasvolumetricanalysisandconsistsoftitratingtheunknownsolutionwiththeone2ofknownconcentration(astandardsolution).Bytitration,youcandetermineexactlyhowmuchofareagentisrequiredtobringaboutcompletereactionofthetestsolution.Usually,completionofthereactionisindicatedbyasudden,visiblechangeinthereactionsystemthatcoincideswiththestoichiometricrelationshipbetweenmolesorequivalentsof-thereagentsolutionandthereactantinthetestsolution,Adroportwoofanappropriateindicatorsolutionproducesacolorchangeatthepointwherethereactioniscomplete-referredtoastheendpoint.化學分析是用来确定要用多少已知浓度的溶液与未知试样完全反应。這种措施就是壹般所說的容量分析，它用壹种已知溶液（原则溶液）標定未知溶液。通過滴定，你能精确的懂得需要多少试剂才能导致（使）待测溶液完全反应。壹般，反应的完毕是通過在反应体系中的忽然的可見的变化来表明的，而這种突变和试剂溶液与待测溶液中的反应物的摩尔或當量的化學计量关系壹致，壹两滴合适的指示剂溶液在反应完毕，也就是反应终點時产生壹种颜色的变化。Molarityisthenumberofmoles(gram-molecularweights)ofsubstanceperliterofsolution.Themoleweightofsulfuricacidis98.08g,andtherefore,1moleofH2SO4contains98.08g.If49.04garedilutedto1liter