Unit 14: Applications of Organic Chemistry
Accessor:
Date:
i Types, iStructures, iReactions, iUses iand iProperties iof iIsomers
Identified ias imolecules ithat ihave iidentical imolecular iformulas, ithis iis inot iinclusive iof ithe
i structural iarrangements iof iisomers. iThis ioccurs ias ia iresult iof ithe imolecule irevolving ias ia
i whole, ior irevolving iaround ispecific ibonds. iStructural iisomerism ican ibe icategorised iinto
i three igroups, iconclusive iof:
Chain iIsomerism
Comprised iof itwo ior imore icarbon ior iother icompounds iwith ithe isame imolecular
i formula, ichain iisomers iwill idiffer iin iterms iof itheir iatomic iarrangements iand
i branches. i
As iobserved, ipentane ihas ia imolecular iformula iof iC5H12, iwhich iis iequivalent ito ithat
i of ineopentane. iThe idifference ican ibe iacknowledged iin iits istructure iwhere ithe iCH3
i on ithe ineopentane iis iexchanged iwith ithe ihydrogen iatom, ialong iwith ianother iCH3
i group ion ithe iright. iConsequently, ithis iwill ichange ithe iway ithe iatoms ibond
i together iand iresult iin ithem ihaving idifferent iproperties iand ireactions.
For iinstance, ithe iboiling ipoint iof ineopentane iis i10.0∘C iwhile ipentane iis i36.1∘C.
i Neopentane iis imore icondensed ithan ipentane iand ihas iless icontact isurface iarea,
i meaning iit ihas iless iLondon idispersion iforces iof iattraction. iConcerning imelting
i points, ipentane iwill imelt ihigher ithan iits iother iisomer, iisopentane ias iit ican itake ion
i a irodlike ishape iallowing imolecules inear iit ito ipack iclosely itogether. iHowever,
i neopentane imelts imore ithan i100° ihigher ithan ithe iboth iof ithem ias iit itakes ion ia
i spherical ishape, ienabling ithe imolecules iexert irelatively ilittle iattraction ion ieach
i other. iHowever, ithey iare iboth icombustible, icolourless iand ilighter ithan iwater.
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, As idisplayed iabove, ithe istructural idifference iobserved iis ithat in-butane ihas ia
i straight ichain istructure iwhereas iin ithe iiso-butane, iit ihas istraight ichain iis iof ithree
i carbon iatoms. iThe imethyl igroup iin iiso-butane iis ilocated iat icarbon inumber itwo.
i Both iButane iand iIsobutane iare igases, ithey ipractically ihave ino icolour, ibut ihave ia
i characteristic iodour. iThese icompounds iare iflammable iand ithus, ican ibe iused ias
i fuel ifor iburning. iThe imain idifference ibetween ibutane iand iisobutane iis ithat
i butane ican ibe ieither ia ilinear ior ibranched imolecule iwhereas iisobutane iis
i essentially ia ibranched imolecule. iIsobutane ihas ia ivery ilow iboiling ipoint icompared
i to ithat iof inormal ibutane icoming iin iat iaround i-11oC. iThis iis ia iresult iof ithe
i branched istructure iof iisobutane. iAs inormal ibutane iis ia ilinear imolecule ican ihave
i more iVan iDer iWaal iforces ithan ithat iof iisobutane, igiving iit ia iboiling ipoint iof i-1oC.
Functional iGroup iIsomerism
Sharing ithe isame istructural iformula, ifunctional igroup iisomerism ientails ithat ithe
i molecules iwill idifferent ihomologous iseries ior ifamilies iof icompounds. iThis
i transpires iwhen ithe ifunctional igroup iis ireformed ias iatoms iwithin ithe imolecules
i are ibonded itogether iin idifferent iways. i
As idisplayed iabove, ipropanal ihas ian ialdehyde igroup iwith ia ihydrogen iatom
i attached ito ithe icarbonyl igroup. iComparatively, ipropanone iis iclassed ias ia iketone
i with ialkyl ior iaryl igroups iattached ito ithe icarbonyl igroup. iPropanone iwill ihave ino
i hydrogen iatoms iattached ito ithe icarbonyl icarbon. iThey iare iboth icolourless,
i volatile, iflammable iorganic isolvent iwith ithe ichemical iformula i(CH3)2CO.
Additionally, ipropanone ihas ia iboiling ipoint i56 idegrees iCelsius, iwhile ipropanol ihas
i one iof i46 ito i50. iThis iis ibecause ipropanol ihas ihigher iboiling ipoint ithan ipropane
i due ito ihydrogen ibonding, imaking iit iharder ifor ithe imolecules ito iseparate iin iorder
i for ithem ito ienter ithe igas iphase. iPropanone iis iutilised iin ithe imanufacturing iof
i plastics iand icleansers/cleaning isupplies, iwhile ipropanol iis imainly iused ias ia
i solvent.
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Accessor:
Date:
i Types, iStructures, iReactions, iUses iand iProperties iof iIsomers
Identified ias imolecules ithat ihave iidentical imolecular iformulas, ithis iis inot iinclusive iof ithe
i structural iarrangements iof iisomers. iThis ioccurs ias ia iresult iof ithe imolecule irevolving ias ia
i whole, ior irevolving iaround ispecific ibonds. iStructural iisomerism ican ibe icategorised iinto
i three igroups, iconclusive iof:
Chain iIsomerism
Comprised iof itwo ior imore icarbon ior iother icompounds iwith ithe isame imolecular
i formula, ichain iisomers iwill idiffer iin iterms iof itheir iatomic iarrangements iand
i branches. i
As iobserved, ipentane ihas ia imolecular iformula iof iC5H12, iwhich iis iequivalent ito ithat
i of ineopentane. iThe idifference ican ibe iacknowledged iin iits istructure iwhere ithe iCH3
i on ithe ineopentane iis iexchanged iwith ithe ihydrogen iatom, ialong iwith ianother iCH3
i group ion ithe iright. iConsequently, ithis iwill ichange ithe iway ithe iatoms ibond
i together iand iresult iin ithem ihaving idifferent iproperties iand ireactions.
For iinstance, ithe iboiling ipoint iof ineopentane iis i10.0∘C iwhile ipentane iis i36.1∘C.
i Neopentane iis imore icondensed ithan ipentane iand ihas iless icontact isurface iarea,
i meaning iit ihas iless iLondon idispersion iforces iof iattraction. iConcerning imelting
i points, ipentane iwill imelt ihigher ithan iits iother iisomer, iisopentane ias iit ican itake ion
i a irodlike ishape iallowing imolecules inear iit ito ipack iclosely itogether. iHowever,
i neopentane imelts imore ithan i100° ihigher ithan ithe iboth iof ithem ias iit itakes ion ia
i spherical ishape, ienabling ithe imolecules iexert irelatively ilittle iattraction ion ieach
i other. iHowever, ithey iare iboth icombustible, icolourless iand ilighter ithan iwater.
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, As idisplayed iabove, ithe istructural idifference iobserved iis ithat in-butane ihas ia
i straight ichain istructure iwhereas iin ithe iiso-butane, iit ihas istraight ichain iis iof ithree
i carbon iatoms. iThe imethyl igroup iin iiso-butane iis ilocated iat icarbon inumber itwo.
i Both iButane iand iIsobutane iare igases, ithey ipractically ihave ino icolour, ibut ihave ia
i characteristic iodour. iThese icompounds iare iflammable iand ithus, ican ibe iused ias
i fuel ifor iburning. iThe imain idifference ibetween ibutane iand iisobutane iis ithat
i butane ican ibe ieither ia ilinear ior ibranched imolecule iwhereas iisobutane iis
i essentially ia ibranched imolecule. iIsobutane ihas ia ivery ilow iboiling ipoint icompared
i to ithat iof inormal ibutane icoming iin iat iaround i-11oC. iThis iis ia iresult iof ithe
i branched istructure iof iisobutane. iAs inormal ibutane iis ia ilinear imolecule ican ihave
i more iVan iDer iWaal iforces ithan ithat iof iisobutane, igiving iit ia iboiling ipoint iof i-1oC.
Functional iGroup iIsomerism
Sharing ithe isame istructural iformula, ifunctional igroup iisomerism ientails ithat ithe
i molecules iwill idifferent ihomologous iseries ior ifamilies iof icompounds. iThis
i transpires iwhen ithe ifunctional igroup iis ireformed ias iatoms iwithin ithe imolecules
i are ibonded itogether iin idifferent iways. i
As idisplayed iabove, ipropanal ihas ian ialdehyde igroup iwith ia ihydrogen iatom
i attached ito ithe icarbonyl igroup. iComparatively, ipropanone iis iclassed ias ia iketone
i with ialkyl ior iaryl igroups iattached ito ithe icarbonyl igroup. iPropanone iwill ihave ino
i hydrogen iatoms iattached ito ithe icarbonyl icarbon. iThey iare iboth icolourless,
i volatile, iflammable iorganic isolvent iwith ithe ichemical iformula i(CH3)2CO.
Additionally, ipropanone ihas ia iboiling ipoint i56 idegrees iCelsius, iwhile ipropanol ihas
i one iof i46 ito i50. iThis iis ibecause ipropanol ihas ihigher iboiling ipoint ithan ipropane
i due ito ihydrogen ibonding, imaking iit iharder ifor ithe imolecules ito iseparate iin iorder
i for ithem ito ienter ithe igas iphase. iPropanone iis iutilised iin ithe imanufacturing iof
i plastics iand icleansers/cleaning isupplies, iwhile ipropanol iis imainly iused ias ia
i solvent.
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