Alkenes Flashcards
1
Q
Unsaturated molecules
A
- C=C
- contains one or more double bonds
2
Q
Alkene vs alkane boiling point
A
- less surface contact than alkanes
- less induced dipole-dipole forces
- lower boiling point
3
Q
Sigma bond
A
- single covalent bond
- shared pair of electrons
- electron density concentrated between two nuclei
4
Q
Pi bond
A
- sideways overlap of two p-orbitals
- between adjacent carbon atoms
- provides one electron each
- weaker than sigma
5
Q
C=C bond
A
- trigonal planar
- 120 degrees
- three paired electrons
6
Q
Sterioisomerism
A
- same molecular and structural formula
- different 3D spatial arrangement
7
Q
Reasons for sterioisomerism
A
- restricted rotation of C=C double bond
- different 3D arrangement of R groups
8
Q
Solubility
A
insoluble in water
9
Q
CIP rules E isomer
A
- two attached atoms with highest atomic number
- diagonally opposite side of double bond
10
Q
CIP rules Z isomer
A
- two attached atoms with highest atomic number
- not diagonally opposite side of double bond
11
Q
Alkene to alkane
A
Reagent: hydrogen
Conditions: nickel, heat
Mechanism: hydrogenation/ addition
12
Q
Alkene test
A
Reagent: orange bromine water
Observations: decolourisation
13
Q
Alkene to haloalkane
A
Reagent: hydrogen halide / halogen
Mechanism: electrophilic addition
14
Q
Alkene to alcohol
A
Reagent: steam
Conditions: H3PO4, heat, high pressure
Mechanism: hydration
15
Q
Electrophile
A
- electron pair acceptor
- attracted to electron dense regions