Western Connecticut State University Molecular Orbital Theory General Chemistry I CHE 110 These problems are for practice in drawing your molecular orbital diagrams, molecular electron configurations and determining bond order. The following questions pertain to the F2 molecule: A) Draw the molecular orbital energy diagram for this molecule. Label all of the orbitals specifically. B) Give the molecular electron configuration for the molecule:

(σ1s) 2 (σ1s*) 2 (σ2s) 2 (σ2s

*) 2 (σ2px) 2 (π2p) 4 (π2p*) 4

C) Determine the bond order for the molecule:

Bond Order = (10 – 8) / 2 = 1 D) Indicate whether the species is paramagnetic or diamagnetic:

Diamagnetic: No unpaired electrons

F) Compare the relative stability of this molecule to F2

+ and F2-:

F2

+ > F2 > F2- (Based on their Bond Orders)

2p 2p

2s2s

1s 1s

σ2s

π2py

σ*2s

σ*1s

σ1s

σ*2px

σ2px

π2pz

π*2py π*

2pz

Energy

F F1s22s22p5 1s22s22p5

Western Connecticut State University Molecular Orbital Theory General Chemistry I CHE 110 The following questions pertain to the C2

+ ion: A) Draw the molecular orbital energy diagram for this ion. Label all of the orbitals specifically. B) Give the molecular electron configuration for the ion:

(σ1s) 2 (σ1s*) 2 (σ2s) 2 (σ2s

*) 2 (π2p) 3 C) Determine the bond order for the ion:

Bond Order = (7 – 4) / 2 = 1.5 D) Indicate whether the species is paramagnetic or diamagnetic:

Paramagnetic: one unpaired electron

F) Compare the relative stability of this molecule to C2 and C2

-:

C2- > C2 > C2

+ (Based on their Bond Orders)

2p 2p

2s2s

1s 1s

σ2s

π2py

σ*2s

σ*1s

σ1s

σ*2px

σ2px

π2pz

π*2py π*

2pz

Energy

C C+

1s22s22p2 1s22s22p1

Western Connecticut State University Molecular Orbital Theory General Chemistry I CHE 110 The following questions pertain to the NO molecule: A) Draw the molecular orbital energy diagram for this molecule. Label all of the orbitals specifically. B) Give the molecular electron configuration for the molecule:

(σ1s) 2 (σ1s*) 2 (σ2s) 2 (σ2s

*) 2 (σ2px) 2 (π2p) 4 (π2p*) 1

C) Determine the bond order for the molecule:

Bond Order = (10 – 5) / 2 = 2.5 D) Indicate whether the species is paramagnetic or diamagnetic:

Paramagnetic: One unpaired electron

F) Compare the relative stability of this molecule to NO+ and NO--:

NO+ > NO > NO- (Based on their Bond Orders)

2p 2p

2s2s

1s 1s

σ2s

π2py

σ*2s

σ*1s

σ1s

σ*2px

σ2px

π2pz

π*2py π*

2pz

Energy

N O1s22s22p3 1s22s22p4