中国船型开关行业发展调研及投资建议...

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1、24.1PetroleumRefiningandtheHydrocarbons24.2FunctionalGroupsandOrganicSynthesis24.3PesticidesandPharmaceuticalsChapter24FromPetroleumtoPharmaceuticals1PhysicalPropertiesofAlkanesandCycloalkanesWhydomoleculestendtosticktogether?2increasewithincreasingnumberof

2、carbonsmoreatoms,moreelectrons,moreopportunitiesforinduceddipole-induceddipoleforcesdecreasewithchainbranchingbranchedmoleculesaremorecompactwithsmallersurfacearea—fewerpointsofcontactwithothermoleculesBoilingPoints3CH4n-C4H10n-C7H16n-C8H18n-C6H14Boilin

3、gpointsandmeltingpointsofn-alkanes4increasewithincreasingnumberofcarbonsmoreatoms,moreelectrons,moreopportunitiesforinduceddipole-induceddipoleforcesBoilingPointsHeptanebp98°COctanebp125°CNonanebp150°C5BoilingPointsn-octane:bp125°C2-Methylheptane:bp118°

4、C2,2,3,3-Tetramethylbutane:bp107°Cdecreasewithchainbranching(WHY?)branchedmoleculesaremorecompactwithsmallersurfacearea—fewerpointsofcontactwithothermolecules6BoilingPointsofAlkanesgovernedbystrengthofintermolecularattractiveforcesalkanesarenonpolar,sodip

5、ole-dipoleanddipole-induceddipoleforcesareabsentonlyforcesofintermolecularattractionareinduceddipole-induceddipoleforces7Induceddipole-Induceddipoleattractiveforces+–+–twononpolarmoleculescenterofpositivechargeandcenterofnegativechargecoincideineach8Induced

6、dipole-Induceddipoleattractiveforces+–+–movementofelectronscreatesaninstantaneousdipoleinonemolecule(left)9Induceddipole-Induceddipoleattractiveforces+–+–temporarydipoleinonemolecule(left)inducesacomplementarydipoleinothermolecule(right)10Induceddipole-Indu

7、ceddipoleattractiveforces+–+–temporarydipoleinonemolecule(left)inducesacomplementarydipoleinothermolecule(right)11Induceddipole-Induceddipoleattractiveforces+–+–theresultisasmallattractiveforcebetweenthetwomolecules12Induceddipole-Induceddipoleattractivefor

8、ces+–+–theresultisasmallattractiveforcebetweenthetwomolecules13StraightchainhydrocarbonBranchedhydrocarbonLotsofintermolecularcontactsFewerintermolecularcontacts14Smallorganicmolecules:requiredtosustai