化学专业英语ppt课件

Lesson2THECLASSIFICATIONOFINORGANICCOMPOUNDS无机化合物分类 词汇 TheClassesofCompounds1 Thousandsandtensofthousandsofcompoundsareknowntothechemisttoday Itwouldbeimpossibletolearnpropertiesandbehaviorofevenafractionofthisnumberifithadtobedoneonthebasisofindividualcompounds Fortunately mostchemicalcompoundscanbegroupedtogetherinafewclasses Then ifwecanproperlyclassifyacompound weareatonceawareofthegeneralpropertiesofthecompoundfromknowledgeofthepropertiesofthatclassorgroupofcompounds Forexample HClisclassedasanacid andbybecomingfamiliarwiththebehaviorofacidsasadistinctclass weareatonceawareofthegeneralpropertiesofthecompound Agreatmanyofthecompoundswearetostudymaybeclassifiedasacids bases salts metallicoxides ornonmetallicoxides Ofthesefiveclassesofcompounds thefirstthree acids bases andsalts arebyfarthemostimportant TheClassesofCompoundsThousandsandtensofthousandsofcompoundsareknowntothechemisttoday 化合物分类现今 化学家知道了成千上万的化合物 thousandsandtensofthousands成千上万beknownto被 所知 chem o 化学 的 chemistry化学chemical化学的 化学药品chemosynthesis化学合成 Itwouldbeimpossibletolearnpropertiesandbehaviorofevenafractionofthisnumberifithadtobedoneonthebasisofindividualcompounds 如果根据个别化合物来了解这么多化合物的性质 即使其中的一小部分也是不可能的 afractionof一小部分onthebasisof根据 在 基础上 Fortunately mostchemicalcompoundscanbegroupedtogetherinafewclasses 幸运的是 大多数化合物能够组合在一起分成几类 Then ifwecanproperlyclassifyacompound weareatonceawareofthegeneralpropertiesofthecompoundfromknowledgeofthepropertiesofthatclassorgroupofcompounds 那么 如果我们能够恰当地将一个化合物归类 我们立刻就能从这类化合物的性质来了解这个化合物的一般性质 beawareof知道 意识到 Forexample HClisclassedasanacid andbybecomingfamiliarwiththebehaviorofacidsasadistinctclass weareatonceawareofthegeneralpropertiesofthecompound become be familiarwith 熟悉 通晓 例如 盐酸归类为酸 由于已熟悉作为不同类别的酸的性质 我们就会立即知道这一化合物的一般性质 Agreatmanyofthecompoundswearetostudymaybeclassifiedasacids bases salts metallicoxides ornonmetallicoxides Ofthesefiveclassesofcompounds thefirstthree acids bases andsalts arebyfarthemostimportant 我们将要研究的众多化合物可以分类为酸 碱 盐 金属氧化物或非金属氧化物 这五类化合物中的前三类 酸 碱和盐 是最重要的 agreat good manyof很多 大量 2 Whenanacid base orsaltisdissolvedinwatertheresultingsolutionisaconductoroftheelectriccurrentandistermedanelectrolyte Ifnoconductionofcurrentoccurs thecompoundisknownasanonelectrolyte 2 Whenanacid base orsaltisdissolvedinwatertheresultingsolutionisaconductoroftheelectriccurrentandistermedanelectrolyte Ifnoconductionofcurrentoccurs thecompoundisknownasanonelectrolyte 酸 碱或盐溶于水中得到的溶液是电流的导体 它们被定义为电解质 如果没有电流的传导发生 这种化合物被称为非电解质 conductor导体electriccurrent电流term被称作electrolyte nonelectrolyte电解质 非电解质 3 ClassificationofCommonCompoundsBylookingatthechemicalformulaswemayclassifymanycommoncompoundsinthefollowingway 1 Acids intheconventionalsense mayberecognizedbynotingthattheHiswrittenfirstintheformulaandthattherestofthecompoundisgenerallynonmetallic Ex HCl H2SO4 HClO 2 ConventionalbaseshaveOHradicalswrittenlastintheformula Thefirstpartoftheformulaisusuallyametal Ex NaOH Ca OH 2 Fe OH 3 3 Asaltconsistsofametal writtenfirst combinedwithanon metalorradicalwrittenlastinaformula Ex NaCl Fe2 SO4 3 Ca ClO 2 4 Oxidesarecompoundscontainingoxygenandonlyoneotherelement ClassificationofCommonCompoundsBylookingatthechemicalformulaswemayclassifymanycommoncompoundsinthefollowingway 普通化合物分类我们可以根据化学式按着下面的方法分类许多普通化合物 Classn 类别ClassifyVt 分类Classificationn 分类 1 Acids intheconventionalsense mayberecognizedbynotingthattheHiswrittenfirstintheformulaandthattherestofthecompoundisgenerallynonmetallic Ex HCl H2SO4 HClO intheconventionalsense按传统的观念 常识 1 按传统的观念 可以通过在分子式中将H写在第一位并且化合物中的其余部分通常是非金属来辨认出酸 例如 HCl H2SO4 HClO 2 ConventionalbaseshaveOHradicalswrittenlastintheformula Thefirstpartoftheformulaisusuallyametal Ex NaOH Ca OH 2 Fe OH 3 2 传统碱的分子式中将OH基写在最后面 分子式的第一部分通常是一种金属 例如 NaOH Ca OH 2 Fe OH 3 3 Asaltconsistsofametal writtenfirst combinedwithanon metalorradicalwrittenlastinaformula Ex NaCl Fe2 SO4 3 Ca ClO 2 3 盐的分子式由写在第一位的金属和写在最后一位的非金属或原子团组成 例如 NaCl Fe2 SO4 3 Ca ClO 2 4 Oxidesarecompoundscontainingoxygenandonlyoneotherelement 4 氧化物是由氧和唯一一种其它元素组成的化合物 4 Iftheelementotherthanoxygenisanonmetal theoxideclassedasanonmetaloxideoranacidicanhydride Thelatternamecomesaboutbecausewateraddedtononmetaloxidesundercertainconditionsproducesacids Likewise ifwaterisremovedfromanacidcontainingoxygen theacidanhydride withoutwater results Iftheelementotherthanoxygenisanonmetal theoxideclassedasanonmetaloxideoranacidicanhydride otherthan除了 不同于anhydride酐anhydr o 脱水 无水 酐anhydration脱水 干化anhydrous无水的anhydroglucose脱水葡萄糖 如果除氧以外的元素是非金属 这种氧化物被称为非金属氧化物或酸酐 Thelatternamecomesaboutbecausewateraddedtononmetaloxidesundercertainconditionsproducesacids 酸酐的名称来源于在一定条件下将水加到非金属氧化物中能够生成酸 comeabout产生 发生 出现 Likewise ifwaterisremovedfromanacidcontainingoxygen theacidanhydride withoutwater results 同样 如果将水从含氧酸中除去 就会生成酸酐 没水 acidcontainingoxygen含氧酸 5 Theotherclassofoxides metallicoxidesorbasicanhydrides consistofoxygencombinedwithametal Whenwaterisaddedunderproperconditionstobasicanhydrides basesresultandviceversa Theotherclassofoxides metallicoxidesorbasicanhydrides consistofoxygencombinedwithametal basicanhydride碱酐 另一类氧化物 金属氧化物或碱酐 由氧和一种金属组成 Whenwaterisaddedunderproperconditionstobasicanhydrides basesresultandviceversa 在合适的条件下将水加到碱酐中就会产生碱 反之亦然 viceversa反之亦然 6AcidsAllacidsintheconventionalsensecontainhydrogen whichmaybereplacedbymetals Thenegativeportionoftheacidmoleculeiscomposedofanonmetaloraradical negativevalencegroup Thesenegativevalencegroups exceptoxideandhydroxide areoftenreferredtoacidradicals Allacidsarecovalentcompoundsinwhichtheatomsareheldtogetherbyasharingofelectrons Whenanacidisdissolvedinwater ionsareformedasaresultofthetransferofahydrogenion proton fromtheacidmoleculetothewatermolecule forexample AcidsAllacidsintheconventionalsensecontainhydrogen whichmaybereplacedbymetals 酸按传统意义 所有酸都含有氢 并且氢能够被金属取代 Thenegativeportionoftheacidmoleculeiscomposedofanonmetaloraradical negativevalencegroup 酸分子中负电部分由一种非金属或原子团 负价基团 组成 Radical根 原子团 Thesenegativevalencegroups exceptoxideandhydroxide areoftenreferredtoacidradicals 这些负价基团 除氧化物和氢氧化物外 通常被定义为酸根 valence化合价acidradicals酸根 Allacidsarecovalentcompoundsinwhichtheatomsareheldtogetherbyasharingofelectrons 所有酸都是共价化合物 在化合物中原子通过电子共享结合在一起 covalentcompounds共价化合物 Whenanacidisdissolvedinwater ionsareformedasaresultofthetransferofahydrogenion proton fromtheacidmoleculetothewatermolecule forexample 当酸溶于水中 酸分子中的氢离子 质子 从酸中迁移到水分子中形成离子 例如 7 Thisisacaseofcoordinatevalence inwhichanunusedpairofelectronsfromthewatermoleculecombineswithahydrogeniontofromahydroniumion Thehydroniumionisahydratedhydrogenionorproton H H2O and whiletheionizationofacidsinaqueoussolutiondependsonitsformation weshallordinarilyusethesimpleH inwritingequations Suchequationsaretherebysimplifiedandeasiertobalance Thisisacaseofcoordinatevalence inwhichanunusedpairofelectronsfromthewatermoleculecombineswithahydrogeniontoformahydroniumion 这是配位键的一个例子 在配位键中水分子中未被使用的电子对同氢离子结合形成水合氢离子 coordinatevalence配位键combinewith与 结合hydroniumion水合氢离子 Thehydroniumionisahydratedhydrogenionorproton H H2O and whiletheionizationofacidsinaqueoussolutiondependsonitsformation weshallordinarilyusethesimpleH inwritingequations Suchequationsaretherebysimplifiedandeasiertobalance 水合氢离子是一种含水的氢离子或质子 H H2O 并且酸通过形成水合氢离子在水溶液中电离 在书写方程式时 我们通常写成简单的H 因此 方程式被简化了 并且更容易配平 hydroniumion hydratedhydrogenion水合氢离子Hydrate与水化合 Hydrated与水化合的 含水的Ionization离子化 电离Equations方程式Thereby因此 8 Thechiefcharacteristicofanacidisitsabilitytofurnishhydrogenions protons therefore anacidisusuallydefinedasasubstancewhichmayfurnishprotons Thechiefcharacteristicofanacidisitsabilitytofurnishhydrogenions protons therefore anacidisusuallydefinedasasubstancewhichmayfurnishprotons furnish提供 供给bedefinedas定义为 酸的主要性质是能够提供氢离子 质子 因此 酸通常被定义为能够提供质子的物质 9 PropertiesofAcids Ingeneral aqueoussolutionsofacidsarecharacterizedbythefollowingproperties 1 Theyhaveasourtaste Lemons oranges andothercitrusfruitsowetheirsourtastetothepresenceofcitricacid thetasteofsourmilkisduetothepresenceoflacticacid 2 Theyturnbluelitmuspaperred Litmusisadyewhichhasaredcolorinacidsolutionandabluecolorinbasicsolution paperwhichhasbeensoakedinlitmusisreferredtoaslitmuspaper Substancesofthistype whichenableustodeterminewhetheragivensolutionisacidorbasic arecalledindicators Methylorangeandphenolphthaleinareotherindicatorsfrequentlyusedbychemists 3 Theyreactwithcertainmetalstoproducehydrogen Reactionsofthistypewerestudiedinconnectionwiththepreparationofhydrogen 4 Theyreactwithbasestoproducesaltsandwater PropertiesofAcids Ingeneral aqueoussolutionsofacidsarecharacterizedbythefollowingproperties 酸的性质 通常 酸的水溶液具有下面的性质 aqueous水的properties性质 1 Theyhaveasourtaste Lemons oranges andothercitrusfruitsowetheirsourtastetothepresenceofcitricacid thetasteofsourmilkisduetothepresenceoflacticacid 1 它们有酸味 柠檬 橙子和其它柑桔属水果由于含有柠檬酸而有酸味 酸牛奶的酸味是由于乳酸的存在 2 Theyturnbluelitmuspaperred Litmusisadyewhichhasaredcolorinacidsolutionandabluecolorinbasicsolution paperwhichhasbeensoakedinlitmusisreferredtoaslitmuspaper 2 它们使蓝色石蕊试纸变红 石蕊是一种在酸溶液中显红色 在碱溶液中显蓝色的染料 已经被浸渍在石蕊中的纸称为石蕊试纸 Substancesofthistype whichenableustodeterminewhetheragivensolutionisacidorbasic arecalledindicators Methylorangeandphenolphthaleinareotherindicatorsfrequentlyusedbychemists enable to使 能够Indicators指示剂Methylorange甲基橙phenolphthalein酚肽 能够用来确定某一特定溶液是酸性或碱性的这类物质称为指示剂 甲基橙和酚酞是经常被化学家使用的另一些指示剂 3 Theyreactwithcertainmetalstoproducehydrogen Reactionsofthistypewerestudiedinconnectionwiththepreparationofhydrogen 4 Theyreactwithbasestoproducesaltsandwater 3 它们和某些金属反应产生氢气 这类反应在氢气制备方面被研究 4 它们和碱反应生成盐和水 inconnectionwith与 有关 在 方面 10 CommonstrongacidsareH2SO4 HNO3 HCl HBr andHI Mostotheracidsaregenerallyonlypartiallyionizedandconsequentlyonlymoderatelystrongorweak CommonstrongacidsareH2SO4 HNO3 HCl HBr andHI Mostotheracidsaregenerallyonlypartiallyionizedandconsequentlyonlymoderatelystrongorweak 普通的强酸有H2SO4 HNO3 HCl HBr和HI 大多数其它酸通常只部分电离 因此它们只是中强酸或弱酸 11 BasesAllmetallichydroxidesareclassedasconventionalbases OfthecommonbasesonlyNaOH KOH Ca OH 2andBa OH 2areappreciablysolubleinwater Ifthesecompoundsaredissolvedinwater theOH iscommontoalloftheirsolutions BasesAllmetallichydroxidesareclassedasconventionalbases OfthecommonbasesonlyNaOH KOH Ca OH 2andBa OH 2areappreciablysolubleinwater Ifthesecompoundsaredissolvedinwater theOH iscommontoalloftheirsolutions appreciably略微 有一点 所有的金属氢氧化物被归类为传统的碱 在普通的碱中 只有NaOH KOH Ca OH 2和Ba OH 2略微可溶于水 如果这些化合物溶于水中 均产生OH AnaqueoussolutionofNH3isalsoclassedasabase sinceOH ionsarepresentinthesolution NH3的水溶液也归类为碱 这是因为在水溶液中存在OH 12 Ineachofthesecompoundswefindacombinationofametal orNH4 withthehydroxidegroup Justasthecharacteristicpartofanacidishydrogenion sothecharacteristicpartofabaseinwatersolutionisthehydroxideion OH Latertheconceptofabasewillbeextendedtoincludesubstanceswhichdonotfurnishhydroxideionsinsolution Ineachofthesecompoundswefindacombinationofametal orNH4 withthehydroxidegroup 我们发现这些化合物中的每一个都由一种金属 或NH4 和氢氧根组成 Justasthecharacteristicpartofanacidishydrogenion sothecharacteristicpartofabaseinwatersolutionisthehydroxideion OH 正如酸的特征部分是氢离子 碱在水溶液中的特征部分是氢氧根离子 OH Justas so 正如 那样 Latertheconceptofabasewillbeextendedtoincludesubstanceswhichfurnishhydroxideionsinsolution 后来 碱的概念被扩展到包括在溶液中没有提供氢氧根离子的物质 13 PropertiesofBases Ingeneral watersolutionsofmetallichydroxides bases exhibitthefollowingproperties 1 Bittertaste 2 Soapyorslipperyfeeling 3 Turnredlitmuspaperblue 4 Reactwithacidstoformsaltsandwater 5 Mostmetallichydroxidesareinsolubleinwater Ofthecommonones onlyNaOH KOH Ca OH 2 Ba OH 2 andNH3aresoluble ThecommonstrongbasesareNaOH KOH Ca OH 2 andBa OH 2 PropertiesofBases Ingeneral watersolutionsofmetallichydroxides bases exhibitthefollowingproperties 碱的性质 通常 金属氢氧化物 碱 具有下面的性质 1 Bittertaste 2 Soapyorslipperyfeeling 3 Turnredlitmuspaperblue 4 Reactwithacidstoformsaltsandwater 1 苦味 2 滑腻感 3 使红色石蕊试纸变蓝 4 同酸反应生成盐和水 5 Mostmetallichydroxidesareinsolubleinwater Ofthecommonones onlyNaOH KOH Ca OH 2 Ba OH 2 andNH3aresoluble ThecommonstrongbasesareNaOH KOH Ca OH 2 andBa OH 2 5 大多数金属氢氧化物难溶于水 普通的氢氧化物中 只有NaOH KOH Ca OH 2 Ba OH 2和NH3是可溶的 普通强碱有NaOH KOH Ca OH 2和Ba OH 2 14 SaltsAnacidreactswithabasetoproduceasaltandwater Hydrogenfromtheacidcombineswithhydroxidefromtheba