Physical Chemistry MO Theory Description for the H2 Molecule Question

Question Description

I’m working on a chemistry multi-part question and need guidance to help me learn.

Compare the MO theory description for the H2 molecule, where the wavefunction is given by equation a:

.ψ=[ψ (1)+ψ (1)][ψ (2)+ψ (2)]

a

.

ψ

=

[

ψ

A

(

1

)

+

ψ

B

(

1

)

]

[

ψ

A

(

2

)

+

ψ

B

(

2

)

]

with the VB treatment given by equation b

b

.

ψ

=

ψ

A

(

1

)

ψ

B

(

2

)

+

ψ

A

(

2

)

ψ

B

(

1

)

+

λ

[

ψ

A

(

1

)

ψ

A

(

2

)

+

ψ

B

(

1

)

ψ

B

(

2

)

]

1. What is the meaning of lambda, λ? [ Select ] [“The contribution of hybrid orbitals“, “The contribution of the molecular dipole“, “The contribution of functions describing ionic character“]

2. Under what condition(s) do the two equations become identical? [ Select ] [“λ>0 and λ<1“, “λ>1 and λ<0“, “λ=1“]

3. How does the MO theory treat the ionic character contribution to the wavefunction? [ Select ] [“The MO theory overestimates the ionic character“, “The MO theory underestimates the ionic character“, “The MO theory correctly estimates the ionic character contribution“]