AP Chemistry Chapter 4

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					                                             AP Chemistry: Chapter 4
Chapter 4: Aqueous Reactions and Solution Stoichiometry
This section presents the fundamental quantitative skills students will need for the rest of the course.

College Board Performance Objectives:
    •    Calculate moles of solute, volume of solution, or molarity of the solution from the other two.
    •    Recognize and solve dilution problems.
    •    Calculate the volume of a certain molarity solution required to react with another solution of known molarity.
    •    Calculate the mass of a substance that would be required to react with a given volume of a solution of known
    •    Calculate mass of solute or concentration of an unknown solution from titration data.

College Board Lab Objectives:
    •    To become familiar with chemical formulas (empirical and molecular) and how they are obtained experimentally.
    •    Learn some basic lab procedures, the chemistry of copper, and the concept of percent yield.

Troubleshooting Tips/Error Traps: Reaction stoichiometry requires a correct, balanced chemical equation.

Key Terms:
                                             metathesis reactions, p. 128                       activity series, p. 142
aqueous solution, p. 121
electrolyte p. 122
                                             molecular, ionic and net ionic equations, p. 129   molarity, p. 146
                                             spectator ions, p. 129                             dilution, p. 148
nonelectrolyte, p. 122
                                             acids and bases, p. 131 (strong and weak)          titration, p. 152
strong and weak electrolytes p. 124
                                             neutralization reaction, p. 134                    standard solution, p. 152
chemical equilbrium, p. 125
                                             salt, p. 134                                       equivalence point, p. 152
solvation p. 123
                                             oxidation-reduction reactions, p. 137              indicators, p. 153
precipitate/precipitation reactions p. 126
                                             oxidation numbers, p. 139                          endpoint p. 153
solubility, p. 127
                                             displacement reactions, p. 140
Summarize: Read Chapter 4 and write a short summary of each of the topics, 4.1-4.6 in your own words.

Homework Exercises: Critical thinking questions and end-of-chapter activities are included in these exercises.
    •    pp. 157–165, Visualizing Concepts: # 4.1, 4.5, 4.9, Electrolytes: #4.15, 4.17, Precipitation Reactions: #4.19,
         4.12, 4.23, 4.25, 4.27, Acid-Base Reactions: #4.29, 4.31, 4.35, 4.37, 4.39, 4.41, 4.43, Oxidation-Reduction
         Reactions: #4.45, 4.47, 4.49, 4.51, 4.52, 4.53, 4.55, 4.57, Solution Composition: 4.69, 4.71, Solution
         Composition: #4.79, 4.85, 4.87, 4.90, 4.92, 4.110 Bonus Problems: 4.113, 4.115.
    •    eMedia Exercises: p. 164, # 4.118, 4.119, 4.120, 4.121.
Student Guide:
Review Chapter 4 and Take the Student Self Test. Note:*Personally select the MOST appropriate 25 problems based on
your learning needs.
         Solution Stoichiometry and Chemical Analysis – Concept Questions
In Chapter 4 your will study the different types of chemical reactions which take place in water solutions. As you study,
focus on what is actually going on in a solution, what species are really present, and how they interact with each other.
One full section of the AP Chemistry Exam is devoted to writing net ionic equations for basic chemical reactions. Set
aside a section in your notes for the basic types of reactions. You will need to refer to these throughout the course and
during your final review for the AP Exam. This chapter is descriptive, yet it includes a review of basic calculations which
will be reinforced in later chapters.
1.     Describe the geometry of a water molecule. Why is the bond angle less than one would expect?
2.     What does the term hydration mean? Explain the energy involved including the terms hydration energy and lattice
3.     Explain the strength of an electrolyte in both operational and conceptual terms.
4.     Describe the purpose of the activities series. What indicator can you use to determine if it is set up in ease of
       oxidation or ease in reduction? (Note: A past AP Exam had the series in reverse order)
5.     Complete the following table regarding the three types of reactions discussed in Chapter 4. Give one sample
       reaction for each.

          Type of Reaction                      Ways to recognize it?               Basic Information-Memorize it!

         Write one example:

         Write one example:

         Write one example:

6.    During a titration you sometimes see a color change before the end point is reached, why does this occur? What
      must you remember to be certain that the end point has been reached? What is the difference between an
      endpoint and an equivalence point?
7.    HCl, HBr, HI are strong acids. Why does HF not follow this trend?
8.    Why does NaOH need to be standardized?
9.    How do you balance a redox equation in the "basic state"?
10. In water, why does the oxygen have more attraction for electrons than the hydrogen?
Memorize: Strong Acids and Bases p.132; Solubility Rules/Tables p.127 and the Rules for Assigning Oxidation Numbers
p. 139.