演示文稿专业英语.ppt

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1、Gas,LiquidandSolidhightemperatureslowtemperaturesKineticEnergyAttractiveIntermolecularForces气体，液体和固体[disˈɔ:də]混乱[ˈpɑ:tikl]微粒[kəmˈpres]压缩[ˈklʌstə]聚集[ˈkrɪstəlaɪn]结晶IonicForces++----+++Ion-Ione.g.NaCl(s)Ion-DipoleIonsformstrongforceswithmoleculewater.Ion-ionforcesareverystrongandproducehighboilingpoint

2、sandmeltingpoints.e.g.NaCldissolvedinwaterIonicLiquids离子间作用力离子-离子离子-偶极分子[ˈaɪən][ˈdaipəul]intermolecular[intə(:)məˈlekjulə]polar[ˈpəulə](Threeimportantintermolecularinteractions)Forces(non-polarmolecules)Forces(polarmolecules)Forces(moleculeswithF-H,O-H,N-Hbonds).[ˌɪntərˈækʃən]相互作用[disˈpə:ʃən][ˈdaipə

3、ul]偶极[ˈhaidrədʒən][ˈbɔndiŋ]分散力氢键IntermolecularInteractionsDispersionDipole-DipoleHydrogenBondingDispersionForcesTheononeatomareattractedtotheonaneighbouringatom.Thiscreatesan“”(i.e.（=idest）temporary)dipoleonthefirstatom.Theinstantaneousdipoleonthefirstatomtheninducesaninstantaneousdipoleontheseconda

4、tom.Thetwoinduceddipolesattracteachother.[ˈhi:li:əm]氦[ˈvændə:ˌwɔ:lz]范德华力[iˈlektrɔn]电子[ˈnju:kliəs]核[ˌɪnstənˈteinjəs]瞬时(vanderWaalsForces)electronsnucleusinstantaneousDispersionForces(vanderWaalsForces)DispersionForcesaretoamolecule’sThepolarizability,theeasewithwhichthee-cloudcanbe,isapproximatelypro

5、portionaltothenumberofelectronsandweight.[ˈpəuləˌraizəˈbiləti]极化率，极化度[prəˈpɔ:ʃənəl]成比例的[dɪˈfɔ:m]使变形[məˈlekjələ]分子的proportionalpolarizabilitydeformedmolecularForexample,theconsistof,non-polaratoms……Asthemolecule(atom)increasesinsize,theboilingpointincreases,sodoesthepolarizability,thereforedispersio

6、nforcesincrease.DispersionForcesalsodependuponthemolecularshape.惰性气体[ˈsfɪərɪkəl]球形的NeonArgon[ˈɑ:ɡɔn]Krypton[ˈkriptɔn]Xeon[ˈzenɔn]sphericalnoblegases[ni:ən]Dipole-DipoleForcesInliquidsofpolarmolecules,oppositelyendsofthemoleculestendtoattracteachother,causingpartial.FormoleculesofroughlyequalMW’s(i.e

7、.withsimilarDispersionForces),themoleculewiththehigherwillhaveahigherboilingpointduetogreaterDipole-Dipoleforces.Propane,MW=44Acetonitrile,MW=410NoDipoleMoment,Tbp=-42oC=3.9Debye(D)LargeDipoleMomen