EX3 MO Supplement (with Answers)

ex3 MO supplement Diagram 9‐1 The molecular orbital diagram below may be used for the following problem(s). For oxygen and fluorine, the σ2p orbital should be lower in energy than the π2p. However, the diagram will still yield correct bond order and magnetic behavior for these molecules. Energy ________ ________ σ*2p ________ ________ ________ π*2p σ2p ________ ________ σ*2s ________ σ2s ________ σ*1s ________ σ1s π2p 1. Refer to Diagram 9‐1. According to molecular orbital theory, which of the following species is the most likely to exist (i.e., which will have the greatest bond order)? a. H22+ b. F22– c. N22– d. Be2 e. O22+ 2. Refer to Diagram 9‐1. According to molecular orbital theory, which of the following species is least likely to exist (i.e., has the lowest bond order)? b. F22+ a. H22– c. C22– d. O22+ e. B22– 3. Refer to Diagram 9‐1. According to molecular orbital theory, which of the following species has the highest bond order? a. F2 b. F22+ c. C22– d. Li2 e. B22+ 4. Refer to Diagram 9‐1. According to molecular orbital theory, what is the bond order of oxygen, N22–? a. 1 b. 3/2 c. 2 d. 5/2 e. 3 5. Refer to Diagram 9‐1. According to molecular orbital theory, what is the bond order of O2+? a. 1 b. 3/2 c. 2 d. 5/2 e. 3 6. Refer to Diagram 9‐1. According to molecular orbital theory, which of the following lists ranks the fluorine species in terms of increasing bond order? F22+ < F22– < F2 F22– < F2 < F22+ F2 < F22+ < F22– F2 < F22– < F22+ F22+ < F2 < F22– a. b. c. d. e. 7. Refer to Diagram 9‐1. Consider the molecules B2, C2, N2 and F2. Which two molecules have the same bond order? a. B2 and C2 b. B2 and F2 c. C2 and N2 d. C2 and F2 e. N2 and F2 8. Refer to Diagram 9‐1. Use molecular orbital theory to predict which species is paramagnetic. a. N2 b. B2 c. F2 d. Li2 e. H2 9. Refer to Diagram 9‐1. Use molecular orbital theory to predict which ion is paramagnetic. a. F22+ b. O22– c. O22+ d. N22+ e. B22– 10. Refer to Diagram 9‐1. What is the molecular orbital configuration of F2? a. [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 (σ2p)2 (σ*2p)2 b. [core electrons] (σ2s)2 (σ*2s)2 (π2p)2 (σ2p)2 (π*2p)2 c. [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 (π*2p)4 d. [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 (σ2p)2 (π*2p)6 e. [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 (σ2p)2 (π*2p)4 11. Refer to Diagram 9‐1. What is the molecular orbital configuration of N22+? a. [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 (σ2p)2 (π*2p)2 b. [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 c. [core electrons] (σ2s)2 (σ*2s)2 (π2p)2 (σ2p)2 d. [core electrons] (σ2s)4 (σ*2s)4 e. [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 (σ2p)2 (π*2p)4 12. Refer to Diagram 9‐1. Assume that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule. What is the molecular orbital configuration of CO? [core electrons] (σ2s)2 (σ*2s)2 (π2p)4 (σ2p)2 [core electrons] (σ2s)2 (σ*2s)2 (π2p)2 (σ2p)2 (π*2p)2 [core electrons] (σ2s)2 (σ*2s)2 (π2p)2 (σ2p)4 [core electrons] (σ2s)2 (σ*2s)2 (π2p)6 [core electrons] (σ2s)2 (σ*2s)2 (π2p)3 (σ2p)3 a. b. c. d. e. 13. Refer to Diagram 9‐1. Assuming that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule, determine which of the following species has the highest bond order. a. NO– b. OF– c. C2 d. O22– e. NO+ 14. Refer to Diagram 9‐1. Assuming that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule, determine which of the following species is paramagnetic. a. NO+ b. CO c. CN– d. OF– e. NO ex3 MO supplement Answer Section 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. E A C C D B B B A E B A E E