CH 223 Chapter Guides

Chapter Guide Four: Overview | Resources | Practice

  Overview of Chapter Guide Four

This module has two portions. The first portion (covered in Chapter Fifteen) explores the important chemical concept of solubility, or how to know when a reactant (or solute) becomes insoluble. The second portion (Chapter 16, which goes roughly up until the beginning of Gibbs Free Energy) explores the concepts of entropy and directionality of reactions.

Chapter 15 revisits solubility from CH 221, but we will examine it in considerable more detail using our understanding of equilibrium. We shall learn about the solubility product constant, Ksp, and know how it relates to a substance's solubility in solution. We shall be able to use Ksp to determine how much solute will dissolve in a given amount of solvent. We shall also be able to use solubility to separate mixtures, and we will use the common ion effect to manipulate solubility.

For a complete list of important concepts in Chapter 15, see the Chapter 15 Study Guide.

Chapter 16 introduces us to entropy, ΔS . We shall discover that the directionality of a reaction (i.e. does it occur? will products form?) is related directly to the disorder of a reaction, otherwise known as its entropy. We shall combine enthalpy, ΔH, with entropy to see if reactions occur or not.

For a complete list of important concepts in Chapter 16, see the Chapter 16 Study Guide.

  Resources for Chapter Guide Four

For this module, you should read Chapter 15 and Chapter 16 (up to Gibbs Energy) in your textbook.

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

The Chapter Fifteen lecture notes and Chapter Sixteen lecture notes which accompany this lesson will be helpful to you when going through this section. These are Web versions of the lecture notes I use in my "normal" CH 223 class and should let you see what is important to me in this chapter. You can also view the Lecture Notes in presentation software for Chapter 15 (Keynote, PowerPoint) and Chapter 16 (Keynote, PowerPoint).

A variety of handouts are available from Chapter Fifteen and Chapter Sixteen. 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 Fifteen Concept Guide and the Chapter Sixteen Concept Guide for a series of worked problems relating to this module. They will help you to ensure the mastery of the knowledge from this section.

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 me to receive extra credit.

  1. Slightly Soluble Salts
  2. The Common Ion Effect
  3. Predicting Precipitation

  Practice the Concepts of Chapter Guide Four

Please complete problem set #4 to further explore the ideas of solubility and entropy. Problem set #4 covers several questions from Chapter 15 and Chapter 16, 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 #4 (with answers included at the end) and/orthe non-assigned problems in Chapter 15 and Chapter 16. 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.

TTest your mastery of the subject matter by trying the self quiz for Chapter 15. This is an ungraded test that you can use to gauge your comfort level with these concepts. This sample Quiz #4 (answers) (which was given during a previous year's CH 223 class) will help you understand the kind of questions that will be asked on the quiz.

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