Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Molecular Orbital Theory Study Guide for Chemistry 201, Study Guides, Projects, Research of Inorganic Chemistry

This study guide for chemistry 201 covers the molecular orbital theory, including basic concepts, homonuclear and heteronuclear diatomic molecules, polyatomic molecules, and applications. It includes topics such as limitations of lewis electron-dot structures and valence bond theory, bonding and anti-bonding molecular orbitals, 3-center, 2-electron bonds, and the role of molecular orbital theory in metallic bonding.

What you will learn

  • How does Molecular Orbital Theory explain the delocalized approach to bonding?
  • What are the limitations of Lewis electron-dot structures and Valence Bond Theory?
  • How does the 3-center, 2-electron concept account for certain molecules such as H3+, BeH2, and B2H6?
  • What is the bond order and how is it related to bond strength and bond distance?
  • How does Molecular Orbital Theory apply to metallic bonding?

Typology: Study Guides, Projects, Research

2020/2021

Uploaded on 11/11/2021

tinbe
tinbe 🇵🇫

1 document

1 / 2

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Chemistry 201
MOLECULAR ORBITAL THEORY
Study Guide
Basic Concepts
1. What are the limitations of (a) the Lewis electron–dot structures, (b) the Valence Bond
Theory? How does the dioxygen molecule, O2, demonstrate these limitations?
2. Valence Bond Theory is described as a localized approach to bonding while Molecular
Orbital Theory is considered a delocalized approach to bonding. Explain the salient points
that distinguish the two theories.
3. How is a molecular orbital different from an atomic orbital?
4. Differentiate the bonding, non–bonding, and the anti–bonding molecular orbitals.
5. What is the bond order? How does one calculate the bond order of a diatomic molecule?
How is the bond order related to bond strength and bond distance?
6. In terms of wave mechanics, what is the theoretical basis for the Molecular Orbital Theory?
Homonuclear and Heteronuclear Diatomic Molecules
7. What simple rule must be remembered when constructing molecular orbital diagrams?
8. Show that the aufbau order, Pauli’s exclusion principle, and Hund’s rule of maximum
multiplicity are still observed in Molecular Orbital Theory.
9. In molecules involving the elements B, C, and N, the 2p and the 2p molecular orbitals
switch places in terms of energy; i.e., the 2p orbital is filled up first. Why is this so?
10. Knowing the molecular orbital diagram for dioxygen, show how it explains the properties of
the molecule that are otherwise not accounted for by Valence Bond Theory.
11. In heteronuclear diatomic molecules, there is unequal contribution from each of the bonded
atoms.
(a) How is this reflected in the molecular orbital diagram?
(b) To which atomic orbital will the character of the bonding molecular orbital be most
similar? Explain.
(c) To which atomic orbital will the character of the anti–bonding molecular orbital be most
similar? Explain.
pf2

Partial preview of the text

Download Molecular Orbital Theory Study Guide for Chemistry 201 and more Study Guides, Projects, Research Inorganic Chemistry in PDF only on Docsity!

Chemistry 201 MOLECULAR ORBITAL THEORY Study Guide Basic Concepts

  1. What are the limitations of (a) the Lewis electron–dot structures, (b) the Valence Bond Theory? How does the dioxygen molecule, O 2 , demonstrate these limitations?
  2. Valence Bond Theory is described as a localized approach to bonding while Molecular Orbital Theory is considered a delocalized approach to bonding. Explain the salient points that distinguish the two theories.
  3. How is a molecular orbital different from an atomic orbital?
  4. Differentiate the bonding, non–bonding, and the anti–bonding molecular orbitals.
  5. What is the bond order? How does one calculate the bond order of a diatomic molecule? How is the bond order related to bond strength and bond distance?
  6. In terms of wave mechanics, what is the theoretical basis for the Molecular Orbital Theory? Homonuclear and Heteronuclear Diatomic Molecules
  7. What simple rule must be remembered when constructing molecular orbital diagrams?
  8. Show that the aufbau order, Pauli’s exclusion principle, and Hund’s rule of maximum multiplicity are still observed in Molecular Orbital Theory.
  9. In molecules involving the elements B, C, and N, the 2p and the 2p molecular orbitals switch places in terms of energy; i.e., the 2p orbital is filled up first. Why is this so?
  10. Knowing the molecular orbital diagram for dioxygen, show how it explains the properties of the molecule that are otherwise not accounted for by Valence Bond Theory.
  11. In heteronuclear diatomic molecules, there is unequal contribution from each of the bonded atoms. (a) How is this reflected in the molecular orbital diagram? (b) To which atomic orbital will the character of the bonding molecular orbital be most similar? Explain. (c) To which atomic orbital will the character of the anti–bonding molecular orbital be most similar? Explain.

Chemistry 201 Polyatomic molecules

  1. What is a 3–center, 2–electron (3c,2e) bond?
  2. How does the 3c,2e concept account for molecules such as H 3 +, BeH 2 , and B 2 H 6?
  3. Spessard and Miessler show a pictorial representation of how polyatomic molecular orbitals are formed. Illustrate this concept using the –allyl and –butadiene.
  4. The same authors show that the same principle may be applied for cyclic systems, with the appreciation that the number of nodes are related to the energy level in the system. (Recall: This is also true for the atom, i.e., the higher the n level, the greater number of nodes.) Illustrate how this is done with benzene. Applications Note : This section may require further reading.
  5. Molecules containing conjugated –bonds often behave as chromophores (from the Greek, meaning color bringer), which are responsible for the absorption of certain wavelengths of light. Show how Molecular Orbital Theory accounts for the absorption of light.
  6. The anti–bonding molecular orbital of carbon monoxide plays a very significant role in the formation of metal carbonyls. How does this orbital participate in bonding? What type of bond is formed? Why is this often called “back–bonding?”
  7. Molecular Orbital Theory is directly applicable to “band theory” in metallic bonding. How does this model account for the properties of metals? References:
  8. Jones, L.; Atkins, P. Chemistry: Molecules, Matter, and Change , 4th^ ed. W. H. Freeman: New York, 2000, p. 400–410.
  9. Whitten, K. W.; Davis, R. E.; Peck, M. L. General Chemistry with Qualitative Analysis , 5th ed. Saunders: New York, 1996, p. 316–332.
  10. Cotton, F. A.; Wilkinson, G.; Gaus, P. L. Basic Inorganic Chemistry , 2nd^ ed. John Wiley & Sons: New York, 1987, p. 95–115.
  11. Zumdahl, S. S. Chemical Principles. D. C. Heath: Lexington, Massachusetts, 1992, p. 613–
  12. Chang, R. Chemistry , 6th^ ed. McGraw–Hill: New York, 1998, p. 396–406.
  13. Petrucci, R. H.; Harwood, W. S. General Chemistry: Principles and Modern Applications , 7th ed. Prentice Hall: New Jersey, 1997, p. 401–408.
  14. Spessard, G. O.; Miessler, G. L. Organometallic Chemistry. Prentice Hall: New Jersey, 1997, p. 15–39. Page 2 of 2