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Alkanes. C. H. n. 2n+2. all C are sp 3 hybridized. bonds. n. root. suffix. formula. 3 prop ane C 3 H 8 4 but ane C 4 H 10 5 pent ane C 5 H 12. 6 hex ane C 6 H 14 7 hept ane C 7 H 16 8 oct ane C 8 H 18 9 non ane C 9 H 20
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Alkanes C H n 2n+2 all C are sp3 hybridized bonds n root suffix formula 3 prop ane C3H8 4 but ane C4H10 5 pent ane C5H12 6 hex ane C6H14 7 hept ane C7H16 8 oct ane C8H18 9 non ane C9H20 10 dec ane C10H22 1 meth ane C H 4 2 eth ane C2H6
Alkanes compound b.p.(Co) m.w. CH4 16 -164 C2H6 30 -88.6 C3H8 44 -42.1 C4H10 58 -0.5 C5H12 72 +36.0 n = 1-4 gases n = 5-15 liquids n > 15 solids
Alkanes IMF = q1q2 n = 1-4 gases ____ r n = 5-15 liquids n > 15 solids LDF q # electrons instantaneous dipole moments
IMF = q1q2 r ____ Alkanes compound b.p. m.w. 72 36.1 72 27.9 72 9.5 structural isomers different shape same formula r branching
Reactions of Alkanes combustion + __ O2 __ CO2 + __ H2O __ C3H8 5 3 4 exothermic reaction combustion with insufficient O2 __ C3H8 + __ O2 __ CO + __ H2O 4 3 7/2 improperly vented spaces and cigarettes
Reactions of Alkanes Substitution of halogens h Cl2 2Cl. step 1 initiation propagation step 2 Cl.+ CH4 CH3. + HCl step 3 CH3.+ Cl2 CH3Cl + Cl. propagation step 4 Cl.+ Cl.Cl2 termination get a mixture of chlorinated methanes
Halogenation of Alkanes methane CH3Cl chloro methyl chloride di CH2Cl2 chloromethane methylene chloride CHCl3 tri chloromethane chloroform tetra CCl4 chloromethane carbon tetrachloride all liquids at room temperature methane is gas e- rich Cl increases LDF
Nomenclature 1. Pick longest C chain as parent 2. Number C beginning at end with first branch 3. Identify branching substituents Assign each a number 4. Use commas to separate numbers hyphens to separate numbers from names 5. Alphabetize substituents
Nomenclature Structural isomers of C5H12 I. III. 4 3 2 1 1 2 3 4 2 3 4 II. 1 1 2 3 I. pentane II. 2- methyl butane III. 2,2- di methyl propane
Nomenclature R = “alkyl” group 1o 3o primary carbon tertiary carbon 4o 2o secondary carbon quaternary carbon
H Nomenclature “common” names to learn: iso propyl alphabetized as i sec- butyl alphabetized as b iso butyl alphabetized as i tert- butyl alphabetized as b