Chapter_8_Exercise_Answers_2016(1)

Chapter_8_Exercise_Answers_2016(1) - ChIRP Chapter 8...

Info icon This preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
ChIRP: Chapter 8 - Exercise Answers (2016) 1 UBC CHEM 111/121 Integrated Resource Package (2016) Chapter 8 - Introduction to Molecular Orbital Theory and Valence Bond Theory PAGE 8.8 1. On the sketches of the MOs for H 2 in Figure 8.3, draw a dotted line where there is a node, if any. The green dotted line indicates a nodal plane in the σ * 1s MO that is perpendicular to the bond axis. PAGE 8.14 1. Sketch the orbital interaction diagram for [H 2 ] and calculate the predicted bond order for this ion. (Note that this diagram is schematic and the energies of the electrons in the atomic orbitals of H and H differ.) E H - [H 2 ] - H Bond order = = ½ 2-1 2
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
ChIRP: Chapter 8 - Exercise Answers (2016) 2 2. Sketch an orbital interaction diagram for elemental hydrogen (i.e., H 2 ) in the first excited state (i.e., σ 1s 1 σ * 1s 1 ). Calculate the predicted bond order. 3. Use molecular orbital theory to provide a rationale for the fact that the molecule He 2 does not exist. PAGE 8.16 1. Determine the Li-Li bond order for Li 2 . The bond order of Li 2 is 1. 2. Write the molecular orbital electronic configuration for Li 2 . The electronic configuration is: σ 1s 2 σ * 1s 2 σ 2s 2 E He He 2 He Bond order = = 0 (therefore He 2 should not exist) 2-2 2 E H H 2 * H Bond order = = 0 1-1 2
Image of page 2
ChIRP: Chapter 8 - Exercise Answers (2016) 3 PAGE 8.20 1. Complete the orbital interaction diagram for dioxygen below by adding the appropriate number of electrons. What feature of the diagram agrees with the prediction that dioxygen is paramagnetic. Assume that the O 2 molecule is oriented along the x-axis. Dioxygen is paramagnetic since the two π * 2 p orbitals each have a single unpaired electron. 2. What is the bond order of O 2 ? The bond order is 2. 3. (a) What is the name of the HOMO in O 2 ? π * 2p (b) What is the name of the LUMO in O 2 ? σ * 2p 2 s 2 s 1 s 1 s σ * 2 s σ 2 s σ * 1 s σ 1 s E x z y 2 p 2 p O O 2 O π 2 p z π 2 p y π * 2 p z π * 2 p y σ 2 p x σ * 2 p x
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
ChIRP: Chapter 8 - Exercise Answers (2016) 4 PAGE 8.20 Complete the energy-level diagrams in Figure 8.6 by placing the appropriate number of electrons in the MOs for each homonuclear diatomic molecule. PAGE 8.23 1. For each of the following ions, i) draw an orbital interaction diagram, ii) calculate the bond order, iii) write the molecular orbital electronic configuration, and iv) classify the species as paramagnetic or diamagnetic. (For the answers below, only the MO portions of the orbital interaction diagrams are shown.) (a) [N 2 ] 2— ii) Bond order: 2 iii) σ 1s 2 σ * 1s 2 σ 2s 2 σ * 2s 2 π 2p 4 σ 2p 2 π * 2p 2 iv) Paramagnetic σ * 2 p σ * 2 s σ 2 s π * 2 p σ 2 p π 2 p σ * 2 p σ * 2 s σ 2 s π * 2 p σ 2 p π 2 p E B 2 C 2 N 2 O 2 F 2 σ * 2 s σ 2 s E σ * 2 p σ 2 p π 2 p π * 2 p σ * 1 s σ 1 s
Image of page 4
ChIRP: Chapter 8 - Exercise Answers (2016) 5 (b) [C 2 ] ii) Bond order: 2.5 iii) σ 1s 2 σ * 1s 2 σ 2s 2 σ * 2s 2 π 2p 4 σ 2p 1 iv) Paramagnetic (c) [O 2 ] 2+ ii) Bond order: 3 iii) σ 1s 2 σ * 1s 2 σ 2s 2 σ * 2s 2 σ 2p 2 π 2p 4
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern