Ikenes onlyappliesfor
unsaturated hydrocarbons with generalformula of onlyan alkenes with 1
unsaturated at least I doublebond double bond
doublebonds have ahighelectron density makesalkenes fairly reactive
e9
I
II IIhave 2 fewer hydrogens than their straightchainversion
cycloalkenes
buta 1,3 diene CHCHCHCH2
it cyclopentane CsHs
ElectrophilicAddition
alkenes attack enes are attacked byelectrophilesdue to their doublebond
which has a highdensity of electrons electrophileadds tomolecule
electrophile electron pairacceptor
e.gl I tvely charged ions no zt Ht
2 polar molecules St H Br H2504
addition of Bromine test for alkenes
addingbromine water to an alkene causes a colourchangefrombrown orang
o colourless testfor alkene decolourationof bromine water
colourless1,2 dibromoethane formed
I t É'd E
Br
BJ Bhaispolarised
CI
I
type Br c
µ
Br sa carbocation intermediate is formed
as the e in doublebondrepelse in Bra
addition of HydrogenHalides
forms halogen oalkanes ethenemintyridardgen'bromide
eg H
Bjj H c
type
reacting with unsymmetrical alkenes
it c c Br
HH bromoethane formed
produces 2 differentproducts amount of 2products isdeterminedby the
ability of the carbocation intermediate
alkyl groupspushe towards the tve carbocation stabilising it the
ore alkyl groupsbonded to the carbocation the more stable it is the more
table the carbocation the more likely it will form
188 Er
It Yambao
ation close c gadgets
carbocation 20 r I I'catriotication so
be.gl
t liar it I of I H of
I ii 1 bromopropane minor produc
rop e ene n
É
s Br Iggy i
addition ofsulfuricacid
c
IIIis it m of
É ii iz bromopropanemajorproduc
H2504 acts as a catalyst in making an alcohol forms an alkylhydrogen
fate intermediate
cIcf n Ethylhydrogen sulfate
g gig tgsIgpti
ti cf.ci o acid is
HzCCHz H2504 CH3CH 20502014 af ensupnateforms
alcoholthroughhydrolysis catalyst
H3CH20502OH H2O CH3 H2OH H2504 asymmetricalalkenescanproduce2product
unsaturated hydrocarbons with generalformula of onlyan alkenes with 1
unsaturated at least I doublebond double bond
doublebonds have ahighelectron density makesalkenes fairly reactive
e9
I
II IIhave 2 fewer hydrogens than their straightchainversion
cycloalkenes
buta 1,3 diene CHCHCHCH2
it cyclopentane CsHs
ElectrophilicAddition
alkenes attack enes are attacked byelectrophilesdue to their doublebond
which has a highdensity of electrons electrophileadds tomolecule
electrophile electron pairacceptor
e.gl I tvely charged ions no zt Ht
2 polar molecules St H Br H2504
addition of Bromine test for alkenes
addingbromine water to an alkene causes a colourchangefrombrown orang
o colourless testfor alkene decolourationof bromine water
colourless1,2 dibromoethane formed
I t É'd E
Br
BJ Bhaispolarised
CI
I
type Br c
µ
Br sa carbocation intermediate is formed
as the e in doublebondrepelse in Bra
addition of HydrogenHalides
forms halogen oalkanes ethenemintyridardgen'bromide
eg H
Bjj H c
type
reacting with unsymmetrical alkenes
it c c Br
HH bromoethane formed
produces 2 differentproducts amount of 2products isdeterminedby the
ability of the carbocation intermediate
alkyl groupspushe towards the tve carbocation stabilising it the
ore alkyl groupsbonded to the carbocation the more stable it is the more
table the carbocation the more likely it will form
188 Er
It Yambao
ation close c gadgets
carbocation 20 r I I'catriotication so
be.gl
t liar it I of I H of
I ii 1 bromopropane minor produc
rop e ene n
É
s Br Iggy i
addition ofsulfuricacid
c
IIIis it m of
É ii iz bromopropanemajorproduc
H2504 acts as a catalyst in making an alcohol forms an alkylhydrogen
fate intermediate
cIcf n Ethylhydrogen sulfate
g gig tgsIgpti
ti cf.ci o acid is
HzCCHz H2504 CH3CH 20502014 af ensupnateforms
alcoholthroughhydrolysis catalyst
H3CH20502OH H2O CH3 H2OH H2504 asymmetricalalkenescanproduce2product
