CH 221 Chapter Guides

Chapter Guide Three: Overview | Resources | Practice


  Overview of Chapter Guide Three

While we learned about the relationship between atoms and elements in the previous section, the goal of this assignment is to learn about the relationship between molecules and compounds. We will also learn the relationship of ions to certain types of compounds. The smallest division of a compound that still has properties of the compound is called a molecule, and we'll be exploring what constitutes a molecule in this chapter. We'll also look extensively at the nomenclature of chemistry - how to "talk the talk" of chemists. In addition, we will begin looking at quantitative chemistry: being able to know "how much" of a compound or element we are adding.

Chapter 2 Part 2 introduces us to a wealth of concepts, and it is important to spend ample time on this chapter learning its contents. We will look at the nomenclature of three main groups of compounds (main group metal plus nonmetal; transition (variable charge) metal plus nonmetal; and nonmetal plus nonmetal). We will delve further into the concept of the mole and understand how to convert a macroscopic quantity (grams) into a counting unit for the subatomic world (number of atoms) using the molar bridge. We will learn about polyatomic ions, and they will assist us in learning the nomenclature rules. We will learn about percent composition, empirical formulas and molecular formulas. We will also look at hydrated compounds and their nomenclature system.

For a complete list of important concepts, see the Chapter 2 Part 2 Study Guide.


  Resources for Chapter Guide Three

For this module, you should read Chapter 2 and Chapter 3.1 - 3.3 in your textbook.

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

The Chapter Two Part 2 Lecture notes which accompany this lesson will be helpful to you when going through this section. These are Web versions of the notes I use in my "normal" CH 221 class and should let you see what is important to me in this chapter. These Polyatomic Flash Cards might prove useful to you as you begin memorizing them for future quizzes and exams.

A variety of handouts are available from Chapter Two. 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 Two Part Two 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 me to receive extra credit.

  1. Simple Nomenclature - Formulas to Names
  2. Simple Nomenclature - Names to Formulas
  3. Transition Metal Nomenclature
  4. Elements, Moles and Mass
  5. Calculating the Molar Mass of a Compound
  6. Mass, Moles and gfw
  7. Word Problems - Elements and Moles
  8. Chemical Formulas and Mass Relationships
  9. Calculations based on Chemical Formulas
  10. Using Molar Volume
  11. Density, Elements, Mass and Moles
  12. Mass, Moles, Density and Volume
  13. Exercises in Comparison
  14. Further Exercises in Comparison
  15. Additional Exercises in Comparison
  16. Percent Composition
  17. Empirical Formulas From Percent Composition

  Practice the Concepts of Chapter Guide Three

Please complete problem set #3 to further explore the molecule and compound concepts. Problem set #3 covers several questions from Chapter 2 Part 2, 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 #3 (with answers included at the end) and/or the non-assigned problems in Chapter 2. Answers to many of those problems are listed in the back of your textbook. Additionally, try this self-graded practice quiz relating to chemical nomenclature in our textbook. In addition, there are two "self quizzes" relating to chemical nomenclature, found here and here.

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.

Test your mastery of the subject matter by trying the self quiz for Chapter 2 Part 2. This is an ungraded test that you can use to gauge your comfort level with these concepts. This sample Quiz #3 (answers) (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.


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