Alkenes Flashcards
Are Alkenes Saturated or unsaturated
UNsaturated
How do Alkenes bond (description)
SP2 hybridisation = sigma bond, and left over p orbitals form a pi-bond,
Functional Group of Alkenes
C=C
what is an E isomer
large groups on opposite sides
Name all electrophilic addition reactions for alkenes
Hydrogenation
Hydration
Halogenation
Explain Hydrogenation of alkene in detail
Alkene + Hydrogen –> Alkane
the pi bond breaks and Hs joins
Needs Ni catalyst
Explain Hydration of alkene in detail
Alkene + Steam —> Alcohol
Phosphoric acid catalyst
Explain Halogenation of alkene in detail
Alkene + HX or X2 —> haloalkane or dihaloalkane
pi-bond breaks and halogen(s) (and/or H) joins on
Explain Addition polymerisation of an alkene
monomers are around the C=C,
C=C breaks and connects to other monomers
First alkene
LOL trick question not one
Second Alkene
Ethene
Propene + Cl2. —->
1,2 di chloro propane
During hetrolytic fission what happens
both electrons go to the atom with the delta negitive
Explain Homolytic fission
One elctron goes to each,
Free radical forms
which is stronger pi or sigma bond
sigma bond, pi bond breaks first
what reaction types do alkenes do
- Electrophilic addition
-Addition Polymerisation
what is a Z isomer
BIG group on same side
why can alkenes create isomers
C=C can’t rotate
catalyst needed when alkene forms alcohol
acid catalyst (such as phosophoric)
Conditions needed for when alkene forms alkane
Ni catalyst
high pressure and temp
conditions needed for alkene –> alcohol
acid catalyist (phosphoric)
high temp and pressure
according to makinokovs rule which is major product
one where the halogen is on the C with most alkyl groups (attached to Cs not H)
General formula of Alkenes
CnH2n
shape and angle of C=C
120 and trigonal planr
are alkenes more or less reactive than alkanes
more as the high e- density of pi-bond and its easier to break than a sigma
