CH 221 Chapter Guides

Chapter Guide Five: Overview | Resources | Practice

  Overview of Chapter Guide Five

The goal of this assignment is to explore the two theories of molecular bonding in use currently. The first model, Valence Bond Theory, is quite useful in most ordinary chemistry scenarios; the other model, Molecular Orbital Theory, requires computers but can be incredibly useful to scientists.

Valence Bond Theory is an extension of the rules outlined in Chapter 4, and we will use hybridization to understand how atomic orbitals combine into molecular orbitals along specific axes. We will also look at the more complicated (but more useful) Molecular Orbital Theory. The Four Principles of Molecular Orbital Theory apply to all systems and help us to understand the Molecular Orbital diagrams. As an example, MO Theory allows us to predict the magnetism (paramagnetic or diamagnetic) nature of molecules, something which is difficult to do in Valence Bond theory.

For a complete list of important concepts, see the Chapter 5 Study Guide.

  Resources for Chapter Guide Five

For this module, you should read Chapter 5 in your textbook.

The following screencasts and Complete Lectures might prove useful to you as you study this chapter.

The Chapter Five Lecture notes which accompany this lesson will be helpful when going through this section. These are Web versions of the lecture notes used in the "normal" CH 221 class and should let you see what is important in this chapter. You can also view the Lecture Notes in presentation software for Chapter 5 (Keynote, PowerPoint).

A variety of handouts are available from Chapter 5. Feel free to explore all of them or just the ones which give you difficulty.

Once you have mastered the concepts listed above, check out the Chapter 5 Concept Guide for a series of worked problems relating to this chapter. They will help you to ensure the mastery of the knowledge from this chapter.

Finally, test yourself (and get extra-credit in the bargain!) on the following chemistry concepts. If you get 9 out of 10 correct (or some multiple thereof), submit the information to receive extra credit.

  1. Hybridization
  2. Hybrid Orbitals

  Practice the Concepts of Chapter Guide Five

Complete problem set #5 to further explore the molecule and compound concepts. Problem set #5 covers several questions from Chapter 5, and it can be found here. We will discuss problems like these during recitation, so come prepared to ask and answer questions.

For additional practice, try completing practice problem set #5 (with answers included at the end) and/or the non-assigned problems in Chapter 5. Answers to many of those problems are listed in the back of your textbook.

If you need assistance on these problems, you have several options. You can visit the AVID / Learning Success Center located above the MHCC library on the Mt. Hood Community College campus; they have tutors available to help you with your chemistry homework. You can also contact me if you have any questions.

This sample Quiz #5 (with answers at the end) which was given during a previous year's CH 221 class will help you understand the kind of questions that will be asked on the quiz.

You can also test your mastery of the subject matter by trying the self quiz for Chapter 5. This is an ungraded quiz that you can use to gauge your comfort level with these concepts.

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The Chapter Guides:

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Questions? Contact me!