Alkanes

Carbonhas4bondingelectrons

Carboncanbondtoitselfinchains

orrings

Carboncanformsingle,doubleand

triplebonds

Carboncanformisomers

(sameformula,differentnames,characteristicsand

properties)

OrganicCompounds• CarbonandHydrogen(bondedtogether)• ExcludingOXIDES,CARBIDES,CARBONATES,CYANIDES

Completestructuraldiagram• i.e.3-methylheptane

CondensedStructuralDiagram

• i.e.3methylheptane

LineStructuralDiagram• AkaSkeletondiagram• i.e.3-methylheptane

ALKANES• Hydrocarboncompounds• AllcarbonsareSATURATED(meaningallsinglebonds)• Acyclic(meaningnoloops)

CnH2n+2• i.e.C7H16

IUPACNaming• therootisnamesusingthelongestcontinuouschainofcarbonatomsandapplyingthestandardgreek name• thesuffix“ane”isaddedtotheappropriatenumbering

Prefix #ofCarbonsMeth 1Eth 2Prop 3But 4Pent 5Hex 6Hept 7Oct 8Non 9Dec 10

• everysidechainisnamedbysubtractingthe“ane”andadding“yl”suffix• eachsidechainisnumberedbyitsdistancefromthefirstcarboninthechain(sotohavethelowestnumbers)

Example

• Namethefollowingalkane

Example2

• Namethefollowingalkane

CH3CH2CHCH2CH3

CH3

Example3

• Namethefollowingalkane

Example4,5,6,7

• 3,3,4,5-tetramethyl decane

• 3-ethyl5-methyloctane

• 4-butyl3-ethyl2,6-dimethylnonane

• 3-ethyl2,3,3-trimethyl heptane

CommercialImportanceofAlkanes

• Naturalgas=mainlymethane(alsoincludesethane,propane,butaneandpentane)• NaturalgasisheatedinafractionaldistillationtowntoremoveH2S

• Petroleum=varietyofalkanesseparatedbyfractionaldistillation• Fuel,wax,lubricants,asphalt,tarandsulfurallcomefrompetroleum• Pharmaceuticals,fertilizers,pesticidesandplasticsaremanufacturedfrompetroleum

PropertiesofAlkanes

• Nonpolarmolecules• asthelengthofthechainincreases,thesumoftheintermolecularforcesincreases

• shapeandsizeaffecttheboilingpoint• Increasethebranchingdecreasestheboilingpoint

• Increasingthenumberofcarbonsincreasestheboilingpoint