Chemical Bonding and Molecular Geometry

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This is a 10 point assignment

Objectives: After completing this unit, students should be able to:

1. Define the terms: ionic bonding, covalent bonding, bond length, bond strength, bond order, dipole moment, and lattice energy.
2. Write the electron configuration of ions of the s- and p- block elements.
3. Define electronegativity and relate the electronegativity of an atom to its position in the periodic table.
4. Classify a bond as nonpolar covalent, polar covalent, or ionic based on the differences in electronegativity.
5. Write Lewis Dot Structures of ionic and covalent compounds and polyatomic ions.
6. Predict relative bond polarities.
7. Write the electronic configurations of ions of s- and p- block elements.
8. Recognize examples of molecules on ions that are exceptions to the octet rule: less than an octet, expanded octet and odd number of electrons.
9. Define resonance (delocalized bonding), recognize when resonance can exist and draw all possible resonance forms of a particular compound or ion.
10. Calculate formal charges of atoms in a molecule or ion.
11. Given a table of bond energies, estimate the enthalpy change for a specified reaction.
12. Define electronegativity and relate the electronegativity of an atom to its position in the periodic table.
13. Relate bond order to bond length and bond strength.
14. Relate the number of electron pairs in the valence shell of an atom in a molecule to their geometrical arrangement of the pairs around the atom.
15. Using Valence Sheel Electron Pair Repulsion (VSEPR) Theory predict the geometry of a molecule or polyatomic ion.
16. Explain how nonbonding electron pairs compress the angles between bonding pairs.
17. Using dot structures, determine the number of sigma and/or pi bonds in a molecule or polyatomic ion given the chemical formula.
18. Predict whether or not a molecule is polar.
19. Explain the concept of hybrid orbitals (sp, sp2, sp3, dsp3, d2sp3) and their relationship to geometrical structures.
20. Based on the Lewis Dot Structure, describe the hybridization, bonding and geometry about the central atom of an ion or molecule.
21. Explain the concept of delocalization in pi bonds.

Reading and Homework Exercises

Table of Contents from: OpenStax Chemistry 2e: Chapter 7, Chapter 8 (sections 8.1-8.3)

Objective 1,3,4 Practice – Questions 1-3 test your ability to identify ionic and covalent(or polar covalent) bonding in compounds.  

You might find the following reading in OpenStax helpful:

Ch 7 Introduction

7.1 Ionic Bonding

7.2 Covalent Bonding

Question 1:

Question 2:

Question 3:

Objective 1,3,4 Practice – Questions 4-9 test your understanding of the periodic trend for electronegativity and your ability to use it in identifying the relative polarity of chemical bonds  

You might find the following reading in OpenStax helpful:

7.2 Covalent Bonding

Question 4:

Question 5:

Question 6:

Question 7:

Question 8:

Question 9:

Objective 5,8-10 Practice – Questions 10-14 test your understanding of Lewis Dot Structures and the information you can get from them.

You might find the following reading in OpenStax helpful:

7.3 Lewis Symbols and Structures

7.4 Formal Charges and Resonance

Question 10:

Question 11:

Question 12:

Question 13:

Question 14:

Objective 9 Practice – Questions 15-16 test your understanding of resonance structures.

You might find the following reading in OpenStax helpful:

7.4 Formal Charges and Resonance

Question 15:

Question 16:

Objectives 11 and 13 Practice – Questions 17-18 test your understanding of relative bond energies and lengths and your ability to estimate heat of reaction using tabulated bond energies.

You might find the following reading in OpenStax helpful:

7.5 Strengths of Ionic and Covalent Bonds

Question 17:

Question 18:

Objective 14, 15, 18-20 Practice – Questions 19-xx test your understanding of the VSEPR theory and your ability to use the theory with dot structures to describe various characteristics of molecules

You might find the following reading in OpenStax helpful:

7.6 Molecular Structure and Polarity

Ch 8 Introduction

8.1 Valence Bond Theory

8.2 Hybrid Atomic Orbitals

Questions 19-23 are for the oxygen difluoride (OF₂) molecule.  HINT: use the Lewis Dot structure you used for the molecule in Question 10.

Question 19:

Question 20:

Question 21:

Question 22:

Question 23:

Questions 24-28 are for the chlorine pentafluoride (ClF₅) molecule.  HINT: use the Lewis Dot structure you used for the molecule in Question 12.

Question 24:

Question 25:

Question 26:

Question 27:

Question 28:

Questions 29-33 are for the triiodide (I₃^–) ion.  HINT: use the Lewis Dot structure you used for the molecule in Question 13.

Question 29:

Question 30:

Question 31:

Question 32:

Question 33:

Objective 17 Practice – Questions 34 and 35 test your ability to determine the number of sigma and pi bonds in a molecule

You might find the following reading in OpenStax helpful:

8.3 Multiple Bonds

Question 34:

Question 35: