Alkene Properties Flashcards
1
Q
structure & bonding
A
1 sigma bond
1 pi bond
double bond shorter and stronger than single bond
2
Q
sp2 hybridized / planar bond angle
A
120º
3
Q
info about pi bond
A
weaker than sigma
will do the chemistry by acting as Nu
restricts rotation
4
Q
electronegativity
A
alkene more EN than an alkane b/c sp2 is e- withdrawing
slightly polar bonds
5
Q
cis vs. trans polarity
A
cis is slightly polar
trans is non-polar b/c dipole cancels
6
Q
HOMO / LUMO
A
HOMO donates e-
LUMO accepts e-
7
Q
cis / trans geometric isomers
A
diastereomers of each other
8
Q
stability order of alkenes
A
more substituted > trans > cis
9
Q
bp/mp
A
BP: Cis > Trans b/c dipole
MP: Trans > Cis b/c trans stacks better (solid like)
10
Q
pka
A
alkene ~ 44 (more acidic)
alkane ~ 50 (less acidic)
sp2 holds (-) closer to nucleus so can stabilize conj. base better
