Properties of alkenes Flashcards
1
Q
define alkene
A
unsaturated hydrocarbon - containing C=C
2
Q
describe sigma bonds
A
- single covalent
- s orbitals overlap
- high bond enthalpy
- very strong
3
Q
describe pi bonds
A
- double covalent
- p orbitals overlap sideways
- lower electron density as they spread above and below
- lower bond enthalpy
- weaker
4
Q
general formula of alkenes
A
CnH2n
5
Q
why are alkenes more reactive than alkanes?
A
the double carbon bond has a high electron density
and the pi bond that is open to attack from electrophiles which makes it very reactive
6
Q
what reaction do alkenes undergo?
A
electrophillic addition
7
Q
state the shape and bond angle of alkenes
A
120 - trigonal planar
8
Q
why can’t double bonds rotate?
A
due to the way p-orbitals overlap to form a pi bond
