Chemistry II AP Objectives

Links:

College Board Topic III:
Reactions

Topics:

1. Reaction types
   1. Acid-base reactions; concepts of Arrhenius, Brønsted-Lowry, and Lewis; coordination complexes; amphoterism
   2. Precipitation reactions
   3. Oxidation-reduction reactions
      1. Oxidation number
      2. The role of the electron in oxidation-reduction
      3. Electrochemistry: electrolytic and galvanic cells; Faraday's laws; standard half-cell potentials; Nernst equation; prediction of the direction of redox reactions

Time Range:
See course calendar

Suggested Teaching Strategies:
1. a. Introduce acid-base behavior in terms of ionization. Use light bulb tester to show acids and bases contain conduct electricity because they contain ions. Good conductors are strong acids and bases, weak conductors are weak acids and bases. Arrhenius definitions are based on these observations.
Bronsted Lowry theory can be introduced by considering things that are known to be acids but are not aqueous solutions. The "accounting system" of naming acids, bases conjugate acids and conjugate bases should be mastered in this segment along with techniques for predicting acid/base pH. Laboratory work with titration and standardization of solutions supports the students concept development.
Lewis definition is presented at the end of this segment as a newer theory that support the observation that metal cations when added to water produce relatively strong acids. This can easily be demonstrated with nitrate salts of sodium, aluminum, calcium and zinc.
Suggest that acid-base definition work is combined with acid-base equilibrium work. See section III. C. 2. b. (1).

2. Solubility rules are presented in Chem I and reviewed in AP Chem. Prediction and quantification of precipitation are covered in section III. C. b. (2).

3. Oxidation - Reduction reactions can be introduced with demos of the reaction between copper sulfate and an iron nail or CuSO₄ and aluminum foil. Oxidation numbers have been taught in Chem I and are reviewed in AP Chem. Students learn to balance reactions based oxidation numbers and to write Redox half reactions. This information is use explain the operation of batteries in terms of two simultaneous but different reactions at each terminal which transfer the electrons through an outer circuit. Student understanding can be encourage through demos of Galvanic cells and laboratory work. Redox is linked to thermodynamics and chemical equilibrium through the Nernst equation.

Aligned Resources:

• Core lab 10 - Electrolytic Cells
• Core lab 11 - Galvanic Cells
• Former Core Lab - Precipitation reactions
• Chem Animations CD
• Brown and LeMay CD
• Wings video on Acids and Bases
• TV Ontario Video on Electrochemistry
• Wright State University video demonstrations

Revision Date:
May 2001