5. Alkenes Flashcards
1
Q
general formula
A
CnH2n
2
Q
what does a C=C consist of
A
one sigma bond
one pi bond
3
Q
Why are pi bonds vulnerable to electrophiles
A
they have a high density
4
Q
how is a sigma bond formed in a C=C
A
one sp2 orbital from each carbon overlap to form a single C-C
5
Q
how is pie bond formed in C=C
A
- sideways overlap with 2 p orbitals
- forms a pie bond above and below the plane of molecule
6
Q
which bond is weaker: pie or sigma
A
Pie bond
7
Q
sterioisomers
A
same structural formulae but different spatial arrangement of atoms
8
Q
why do E-Z isomers exist
A
due to restricted rotation about the C=C
9
Q
when do E-Z isomers arise
A
- restricted rotation around the C=C
- two different groups/atoms attached to the double bond
10
Q
cis isomers
A
same side
11
Q
Trans isomers
A
different sides
12
Q
Alkenes with hydrogen
A
- alkene-> alkane
- reagent: hydrogen
- condition: nickel catalyst
- type of reaction: addition
13
Q
electrophile
A
electron pair acceptor
14
Q
reactions with halogens
A
- reagent: bromine
- condition: rtp
15
Q
mechanism of reaction of alkenes with halogens + type of bond fission
A
electrophillic addition
heterolytic
