Course Icon

Chemistry

Chapter 9: 1-2

SO Icon

Homework

Valence Bonds

Chapter 9: 1-2 Homework

Reading Preparation

Textbook assignment: Read Kotz and Triechel, Chemistry and Chemical Reactivity Chapter 9: Sections 1-2.

Study Notes

9.1: There are two primary ways to explain how atoms share electrons in bonds inside molecules. The two theories have mutually exclusive claims, so they can't simply be joined into one theory. As with wave-particle theories in quantum mechanics, we use whichever theory gives the best results for a given molecule.

9.2: Valence bond theory assumes that two atoms share the electrons that bind them together. As the bonds are formed, electrons shift in relationship to both nuclei to minimize repulsion effects. These shifts can cross orbital types, so that electrons normally in s and p orbitals in the un-attached atom wind up in "standardized" sp orbitals that allow both s and p electrons to participate at the same energy levels.

There are no equations for these sections.

Web Lecture

Read the following weblecture before chat: Valence Bonds

Study Activity

Videos for Chapter 9: Bonding and Molecular Structure

Review the Videos at Thinkwell Video Lessons.

  • Under "Molecular Geometry and Bonding theory: Molecular Geometry and the VSEPR Theory"
    • Valence Shell Electron-Pair Repulsion Theory
    • Molecular Shapes for Steric Numbers 2-4
    • Molecular shapes for Steric Numbers 5&6
    • Predicting Molecular Characteristics Using VSEPR Theory

Simulations

Use the pHET Model simulation below to build each of the molecular shapes in your text, this time with free electron pairs:

  • linear (three atoms, two single bonds)
  • bent (three atoms, two single bonds, two lone pairs)
  • trigonal planar (three atoms around fourth central atom, three single bonds)
  • trigonal pyramidal (three atoms around fourth central atom, three single bonds, one lone pair)
  • tetrahedral (four atoms around fifth central atom, four single bonds)
  • trigonal bipyramidal (five atoms around sixth central atom, five single bonds)
  • octahedral (six atoms around seventh central atom, six single bonds)

Chat Preparation Activities

Chapter Quiz


Lab Work

(Aligns to) AP #7 GUIDED INQUIRY — Conservation of energy effects of disturbing chemical equilibrium — Phase I

Using the resources below, design an experiment to determine how a small change to an equilibrium state affects a reaction. You may observe Le Chatelier's principle by modifying the concentration, volume, temperature, pressure, pH, products, or reactants of a solution at equilibrium, then suggest ways optimize the results of a reaction and increase product yield.

References: