Hydrocarbons alkanes And Alkenes Flashcards
Alkane Chemical properties
Excellent fuels
Completely combust (co2)
Incomplete (CO)
Large alkanes can be cracked into smaller alkanes and alkenes
Alkane general properties
Non polar
Saturated
Sigma bonds
Great flexibility
Bond angles 109.5
# of carbons changes state of matter
Volatile
Less branching means great IMF
Alkane substitution reaction
X2 (g) + UV light yields Haloalkane
Alkene general properties
Double carbon bond
Sigma and pi
CnH2n
Unsaturated
More reactive due to db bonds
Cis trans isomers
Exothermic addition rxns
Alkene to Alkane
Additional rxn
Heat + H2 -catalyst Ni, Pd, Pt—> alkane
Alkene to Alcohol
H20(g)+alkene—> Alcohol
H3PO4 catalyst
Alkene and a halogen (X2)
Halogenation
Addition rxn
Electrophilic addition mechanism
1. X2, inert, plus haloalkane
2. HX at room temp (25 C)
Markovnikov’s rule
When HX is added to an unsymmetrical alkene, the hydrogen becomes attached to the carbon with the most H (major product)
(Minor is the other option)
Alkane with Manganate ion
- Hot, concentrated = alcohol
- Cold, dilute = diol
Alkane to Haloalkane
Substitution rxn
X2 + UV
Free radical substitution rxn
Haloalkane to Amine
Substitution
NH3, in ethanol + heat
Nucleophilic substitution
Haloalkane to Nitrile
Substitution
CN in ethanol, reflux
Nucleophilic substitution rxn
Haloalkane to Alkene
OH- in ethanol
Elimination rxn
Haloalkane to alcohol
Substitution
OH- reflux
Nucleophilic substitution
Alcohol to Haloalkane
Pcl5, PI3, PBr3 or SOCl2
