CHAPTER 20 Electrochemistry
Chapter Opener
__ Chapter Overview, TE Review the objectives listed in the Student Edition.
SECTION 1 Introduction to Electrochemistry
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. Identify parts of the electrochemical cell and their functions.
2. Write electrode half reactions for cathodes and anodes.
FOCUS (5 MINUTES)
__ Lesson Starter, TE Using Figure 1, point out that an increase in temperature indicates
that chemical energy in the form of heat is released.
MOTIVATE (10 MINUTES)
__ Demonstration, Energy in an Electrochemical Cell, TE Have students observe this
electrochemical cell and measure the rise in temperature as an indicator of the generation
of heat.
TEACH (20 MINUTES)
__PowerPoint
__ Discussion, TE Using Figure 2, have students produce their own diagram of an
electrochemical cell, label each part, and answer questions about oxidation, reduction,
electrons, and charge neutrality.
__ Discussion, TE Lead a discussion on the function of a porous barrier in an
electrochemical cell.
__ Inquiry Experiment, Electrical Charge, 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, 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 Voltaic Cells
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. Describe the operation of voltaic cells, including dry cells, lead-acid batteries, and
fuel cells.
2. Identify conditions that lead to corrosion and ways to prevent it.
3. Describe the relationship between voltage and the movement of electrons.
4. Calculate cell voltage/potentials from a table of standard electrode potentials.
FOCUS (5 MINUTES)
__ TE Have student groups discuss types and uses of batteries.
MOTIVATE (10 MINUTES)
__ Demonstration, Fruit Battery, TE Show how slices of fruit can be converted into a
battery
TEACH (65 MINUTES)
__ PowerPoint
__ Visual Strategy, Figure 6, TE Ask students to explain the role of the carbon rod as an
electrode (ADVANCED STUDENTS)
__ Table Strategy, Table 1, Standard Reduction Potentials, TE Call attention to the
change in magnitude and the sign of the standard electrode potential from the top of this
table to the bottom.
__ Sample Problem A, SE Demonstrate how to write the overall cell reaction, and calculate
the cell potential for the given voltaic cell
__ Practice Problems A, SE Students write the overall cell reactions, and calculate the cell
potentials for the given voltaic cells.
__ Chemistry in Action, Fuel-Cell Cars, SE Students can read about the current technology
available for fuel-cell cars. Have students research and compare the characteristics of fuelcell cars from different manufacturers.
__ Discussion, Fuel-Cell Cars, TE Have students research the methods used in this country
to produce hydrogen, in terms of cost, environmental benefits, and feasibility.
__ Math Tutor, Calculating Cell Potentials, SE Students use this exercise to determine the
potentials of different kinds of voltaic cells.
__ Chapter Lab, Inquiry Lab, Making a Potato Battery, SE Students build a battery from
a potato.
__ Datasheet for In-Text Lab, Making a Potato Battery, ANC Students use the datasheet
to complete the Chapter Lab.
__ Forensic and Applied Science Experiments, Micro-Voltaic Cells Students use a
calculator interfaced voltage probe to measure potential differences between various pairs
of half cells. (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 Given a variety of metals in a voltaic cell, students identify
the direction of electron flow, the identity of the anode and cathode, the half-cell reactions
that occur, and the standard electrode potential. (ADVANCED STUDENTS)
OTHER RESOURCE OPTIONS
__ Study Guide, Section Review
__ Section Quiz
__ Additional Practice Problems, EXT Students can get more practice calculating cell
potential.
__ Careers in Chemistry, EXT Go to go.hrw.com for an article on chemical engineering
careers.
SECTION 3 Electrolytic Cells
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. Describe the nature of electrolytic cells.
2. Describe the process of electrolysis in the decomposition of water and in the
production of metals.
3. Explain the process of electroplating.
4. Describe the chemistry of a rechargeable cell.
FOCUS (5 MINUTES)
__ Lesson Starter, TE Discuss the electroplating of jewelry as a common application of
electrochemistry.
MOTIVATE (10 MINUTES)
__ Demonstration, TE Students observe a demonstration of electroplating copper onto a zinc
or iron electrode.
TEACH (20 MINUTES)
__ PowerPoint
__ Visual Strategy, Figure 13, TE Students should make comparisons between the voltaic
cell and the electrolytic cell show in this figure.
__ Demonstration, TE Use a CuSO4 solution, a copper strip, a zinc or iron strip, wires, and
a battery to demonstrate electroplating.
__ Discussion, TE Discuss Faraday’s laws of electrolysis to extend students’ understanding
of the electrolytic process
__ Demonstration, The Electrolysis of KI, TE In a petri dish on an overhead projector,
combine KI solution, phenolphthalein, and starch, then run a small current through the
solution. The students can use their observations to write half-reactions.
__ Chemistry in Action, Sodium Production by Electrolysis, SE Students can read about
the industrial process used to produce sodium.
__ Inquiry Experiment, Electroplating for Corrosion Protection, ANC (ADVANCED
STUDENTS)
CLOSE (10 MINUTES)
__ Section Review, ANC Students answer end-of-section vocabulary, key ideas, critical
thinking, and interpreting graphics questions.
OTHER RESOURCE OPTIONS
__ Study Guide, Section Review
__ Section Quiz
__ Graphing Calculator, Equilibrium Constant for an Electrochemical Cell Go to
go.hrw.com for a graphing calculator exercise that determines the equilibrium constant for
an electrochemical cell.
END OF CHAPTER REVIEW AND ASSESSMENT
__ Chapter Review, SE Students answer questions organized by section and as a mixed
review.
__ Chapter Test A, Electrochemistry, ANC Assign questions for general level chapter
assessment. (GENERAL)
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, Visit www.scilinks.org, maintained by the National
Science Teachers Association, for information on Electrochemical Cells, Electrical
Energy, Batteries, and Electroplating.