Sigma/Pi Bonds and Molecular Orbital Theory Flashcards
What type of orbital overlap occurs in sigma bonds?
End-to-end
In a sigma bond, where is the region of highest electron density?
Along the bond axis
Does a sigma bond allow free rotation of atoms?
Yes
What type of orbital overlap exists in a pi bond?
Side-to-side
Where are the regions of electron density in a pi bond?
There are two regions of electron density: above and below the bond axis
Is a pi bond stronger or weaker than a sigma bond?
Weaker because there is less side-to-side overlap than end-to-end
Does a pi bond allow free rotation of atoms?
No, it restricts rotation
How many sigma and pi bonds are in a single bond?
1 sigma, 0 pi
How many sigma and pi bonds are in a double bond?
1 sigma, 1 pi
How many sigma and pi bonds are in a triple bond?
1 sigma, 2 pi
How do pi bonds create cis and trans isomers?
The pi bonds restrict rotation, allowing two distinct, separate arrangements of atoms
In molecular orbital theory, what are molecular orbitals?
Orbitals that extend over a molecule
The number of molecular orbitals = the number of ?
Atomic orbitals from each atom in a bond
According to molecular orbital theory, how do you find bond order?
(# of bonding orbital e - # of antibonding orbital e)/2
According to molecular orbital theory, how do you know if a molecule is not feasible?
It has a bond order of zero
