Chapter 5 - Molecular Orbitals

Question 1

Answer 1

d orbital: z²

Question 2

Answer 2

d orbital x²-y²

Question 3

Answer 3

d_xy

Question 4

Answer 4

d_yz

Question 5

Answer 5

d_xz

Question 7

π-bond

Answer 7

a change in sign in the wave function with C₂ rotation about the bond axis

one node including the line between nuclei

Question 8

δ-bond

Answer 8

change in sign on C₄ rotation about the bond axis

two nodes including the line between nuclei

Question 13

σ-bond

Answer 13

orbitals are symmetric to rotation about the line connecting the nuclei

no nodes that include the line between nuclei

Question 16

Conditions for formation of molecular orbitals from atomic orbitals

Answer 16

1. Correct symmetry
2. Correct/similar energies
3. Correct/close enough distances

Question 17

The ___ the energy match between atoms, the stronger the interaction

Answer 17

closer/lower

Question 18

Two atomic orbitals have a very large difference in energy. How strong will the interaction between them be?

Answer 18

Very weak. If the atomic orbitals have a very large energy difference, then the resulting molecular orbitals will have energies and shapes closer to the original atomic orbitals.

Question 19

Bond order

Answer 19

Bond order = 1/2 (# bonding electrons - #antibonding electrons)

Question 20

gerade

Answer 20

g = gerade, orbitals symmetric (same sign) on inversion

Question 21

ungerade

Answer 21

u = ungerade, orbitals antisymmetric (signs change) on inversion

Question 22

Orbital mixing

Answer 22

When molecular orbitals have similar (1) symmetry and (2) energies (e.g. σ_g/σ_g*(2s) and σ_g/σ_g*(2p) ), then they can interact to magnify the energy differences–lowering the energy of the lower orbital and raising the nergy of the higher orbital

Question 23

Paramagnetic

Answer 23

Unpaired electrons

Attracted to magnetic field

Question 24

Diamagnetic

Answer 24

Paired electrons

Repulsed by magnetic field

Question 25

What is the relationship between bond order/molecular orbitals and bond length?

Answer 25

As the bond becomes stronger (bond order increases) the bond length decreases.

Question 26

What contribution does electronegativity have on heteronuclear molecular orbitals?

Answer 26

The more electronegative element will have atomic orbitals at lower potential energies than the less electronegative element