Chapter 19 Oxidation-Reduction Reactions
Chapter Opener
__Chapter Overview, TE Review the objectives listed in the Student Edition.
Section 1 Oxidation and Reduction
PACING: 45 minutes
PENNSYLVANIA ACADEMIC STANDARDS FOR SCIENCE AND TECHNOLOGY:
3.1.E.1 Describe how fundamental science and technology concepts are used to solve practical problems.
Objectives
1. Assign oxidation numbers to reactant and product species.
2. Define oxidation and reduction.
3. Explain what an oxidation-reduction (redox reaction) is.
Focus (5 minutes)
__Lesson Starter, TE Review oxidation numbers and have students familiarize themselves with the
rules for assigning oxidation numbers in Table 1.
MOTIVATE (10 minutes)
__Demonstration, A Spontaneous Redox Reaction, TE Demonstrate a redox reaction by using Kl,
KMnO4, and HCl, and make sure students can explain the formation of the precipitate and the color
changes.
TEACH (20 minutes)
__PowerPoint
__Visual Strategy, Figure 1, TE Make sure students understand how this figure illustrates how an
element can exist in a number of different oxidation states. (GENERAL)
__Chemistry in Action, Photochromic Lenses, SE Photochromic eyeglasses darken and become
transparent according to ultraviolet light because of an oxidation-reduction reaction.
__Application, TE Sodium hypochlorite, NaOCl, is the chemical name for household bleach used to
remove stains from clothing through a redox reaction.
__Discussion, TE Students should follow up the spontaneous redox reaction demonstration by
explaining the results in terms of oxidation and reduction and by writing formulas, using Table 1 for
the oxidation numbers.
__Chemistry in Action, Skunk-Spray Remedy, SE Paul Krebaum invented a better way than tomato
juice to get rid of skunk spray odor.
__Chemistry in Action, TE The compounds in skunk spray that have a pervasive odor similar to that of
hydrogen sulfide are mercaptans, organic compounds with the functional group –SH.
__Discussion, Skunk-Spray Remedy, TE Discuss examples of sulfur in both a low and high oxidation
state and talk about possible changes to the reaction in the article.
__Inquiry Experiment, Rust Race, ANC (ADVANCED STUDENTS)
__Microscale Experiment, Oxidation Reduction Reactions, ANC (ADVANCED STUDENTS)
CLOSE (10 minutes)
__Section Review, SE Students answer end-of-section vocabulary, key ideas, critical thinking, and
interpreting graphics questions.
__Alternative Assessment, TE Students observe a reaction of magnesium and HCl and then write the
half-reactions and a complete redox equation.
OTHER RESOURCE OPTIONS
__Study Guide, Section Review, ANC Use this worksheet to assess students’ understanding of the
main concepts presented in the section.
__Section Quiz, ANC Use this quiz to assess students’ understanding of the section.
Section 2 Balancing Redox Equations
PACING: 135 minutes
PENNSYLVANIA ACADEMIC STANDARDS FOR SCIENCE AND TECHNOLOGY:
3.2.A.2 Know that science uses both direct and indirect observation means to study the world and the universe;
3.2.B.1 Describe materials using precise quantitative and qualitative skills based on observations;
3.2.B.2 Develop appropriate scientific experiments: raising questions, formulating hypotheses, testing, controlled
experiments, recognizing variables, manipulating variables, interpreting data, and producing solutions;
3.2.B.3 Use process skills to make inferences and predictions using collected information and to communicate, using
space / time relationships, defining operationally;
3.2.C.1 Generate questions about objects, organisms and/or events that can be answered through scientific
investigations;
3.2.C.2 Evaluate the appropriateness of questions;
3.2.C.4 Conduct a multiple step experiment;
3.2.C.5 Organize experimental information using a variety of analytic methods;
3.2.C.6 Judge the significance of experimental information in answering the question;
3.2.C.7 Suggest additional steps that might be done experimentally;
3.2.D.4 Evaluate the solution, test, redesign and improve as necessary.
Objectives
1. Explain what must be conserved in redox equations.
2. Balance redox equations by using the half-reaction method.
FOCUS (5 minutes)
__Lesson Starter, TE Ask students to balance the equation
MnO 4  I   H 4  MnO 2  I 2  H 2O
MOTIVATE (10 minutes)
__ Reading Skill Builder, Sequencing, TE Students should construct a flowchart or other visual to
represent the sequence they would follow to balance redox equations.
TEACH (110 minutes)
__PowerPoint
__ Problem Solving Workbook, Chapter 23, ANC Students study sample problems and practice
problems involving redox equations. (ADVANCED STUDENTS)
__Discussion, TE Ask students to think about the fact that hydrogen ions and hydroxide ions may be
added when needed even when they are not specified in the equation.
__Sample Problem A, SE Demonstrate how to balance redox reactions
__Practice Problems A, SE Students balance redox reactions.
__Visual Strategy, Figure 4, TE Students should notice the color changes in the reaction addressed in
Sample Problem A.
__Math Tutor, Balancing Redox Equations, SE Students balance redox equations by following two
simple principles.
__Chapter Lab, Microlab, Reduction of Manganese in Permanganate Ion, SE Students perform a
redox titration.
__Datasheet for In-Text Lab, Reduction of Manganese in Permanganate Ion, ANC Students use the
datasheet to complete the Chapter Lab.
__Pre-Lab, Volumetric Analysis, ANC
__Datasheet for In-Text Lab, Pre-Lab Volumetric Analysis, ANC Students use the datasheet to
complete the Pre-Lab.
CLOSE (10 minutes)
__Section Review, SE Students answer end-of-section vocabulary, key ideas, critical thinking, and
interpreting graphics questions.
__Alternative Assessment, TE Students should research the redox reactions that take place in the blackand-white photographic process and write equations for their half-reactions and for the complete redox
reaction. (ADVANCED STUDENTS)
OTHER RESOURCE OPTIONS
__Study Guide, Section Review
__Section Quiz
__Additional Sample Problems, TE Demonstrate how to balance redox equations.
Section 3 Oxidizing and Reducing Agents
PACING: 45 minutes
PENNSYLVANIA ACADEMIC STANDARDS FOR SCIENCE AND TECHNOLOGY:
3.2.A.2 Know that science uses both direct and indirect observation means to study the world and the universe;
3.2.C.2 Evaluate the appropriateness of questions;
3.2.C.5 Organize experimental information using a variety of analytic methods.
Objectives
1. Relate chemical activity to oxidizing and reducing strength.
2. Explain the concept of disproportionation.
FOCUS (5 minutes)
__ Lesson Starter, TE Role-play the terms oxidizing agent and reducing agent by using a small object as
"electrons" and having a student take "electrons" from you.
MOTIVATE (10 minutes)
__Motivation Strategy Ask students to try to explain why ozone, a strong oxidizing agent, can be used
effectively with cold water to clean laundry
TEACH (20 minutes)
__PowerPoint
__Table Strategy, Table 2, Oxidation-Reduction Terminology, TE Introduce students to the table by
asking questions about oxidizing and reducing reactions.
__Table Strategy, Table 3, Relative Strength of Oxidizing and Reducing Agents, TE Use lithium as
an example to point out that strong reducing agents are those that easily give up electrons.
__QuickLab, Redox Reactions, SE In the decomposition of H2O2, the MnO2 acts as a catalyst to speed
up the normally slow reaction
__Datasheet for In-Text Lab, QuickLab Redox Reactions, ANC Students use the datasheet to
complete the QuickLab.
__Inquiry Experiment, Electroplating for Corrosion Protection, ANC
CLOSE (10 minutes)
__Section Review, SE Students answer end-of-section vocabulary, key ideas, critical thinking, and
interpreting graphics questions.
OTHER RESOURCE OPTIONS
__Study Guide, Section Review
__Section Quiz
End of Chapter Review and Assessment
PACING: 45 minutes
__Chapter Review, SE Students answer questions organized by section and as a mixed review.
__Chapter Test A, Oxidation-Reduction Reactions
OTHER RESOURCE OPTIONS
__Standardized Test Prep, SE Have students complete the standardized test prep to help them prepare
for standardized tests.
__SciLinks Visit www.scilinks.org, maintained by the National Science Teachers Association, for
information on Redox Reactions.