# UTPA STEM/CBI Courses/Introduction to STEM/Batteries From Coins

Course Title: Introduction to STEM
Lecture Topic: Batteries From Coins
Instructor: Javier Macossay
Institution: University of Texas - Pan American

## Backwards Design

Course Objectives
* Primary Objectives- By the next class period students will be able to:
** Understand voltaic cells and their chemistry
* Sub Objectives- The objectives will require that students be able to:
** Identify the chemicals in coins.
** Understand the concepts of oxidation and reduction.
** Assemble a voltaic cell.
** Determine the effect of different layers (number of coins).
** Understand the effect of an electrolyte in a voltaic cell.
* Difficulties- Students may have difficulty:
** Students will encounter problems understanding oxidation-reduction reactions.
** Students will encounter problems understanding how a voltaic cell works.
* Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
** Batteries are used everyday in several applications. Examples include disposable batteries used in simple equipment, such as a radio, to rechargeable batteries used in iPods. Furthermore, the advent of electric cars will require the understanding of how batteries work and the development of advanced materials for specialized batteries.
Model of Knowledge
* Concept Map
** Identification of chemicals in coins.
** Understanding oxidation and reduction reactions.
** Assembly of a voltaic cell.
** Evaluation of a voltaic cell with different layers (different number of coins).
** Determination of voltage of the different assemblies.
** Evaluation of a voltaic cell with different layers placing layers of filter paper (saturated with sodium chloride) in between coins.
* Content Priorities
** Enduring Understanding
*** Understand how a voltaic cell works and the importance in powering equipment.
** Important to Do and Know
*** Become familiar with oxidation-reduction reactions.
** Worth Being Familiar with
*** Identification of the chemicals in coins.
Assessment of Learning
* Formative Assessment
** In Class (groups)
*** Discussion of the chemicals in coins.
*** Discussion of voltaic cells and how they work.
*** Discussion of individual laboratory procedures.
*** Discussion of results and conclusions.
** Homework (individual)
*** Internet based search of chemicals used in coins.
*** Internet based search of voltaic cells.
*** Development of a laboratory procedure to assemble and test voltaic cells. A correlation of number of layers and voltage will be made. The effect of sodium chloride on filter paper in between coins should be investigated.
*** Analysis of data and interpretation.
* Summative Assessment
** Discussion in front of the group of the conclusions.

## Legacy Cycle

LOOK AHEAD AND REFLECT BACK
* Goals
** Students should be able to understand the interaction between science and technology and real world applications and impact.
* Objectives
** Students should identify the chemicals used in US coins and learn how to assemble a voltaic cell.
THE CHALLENGE
Duracell is losing market to Energizer, given the fact that the “Bunny” lasts longer and is cheaper. Since you work for the Duracell parent company, you have been assigned to develop alternative ways and materials to launch new, cheaper batteries. You have realized that the majority of the people disregard the US pennies, so can you build a battery from pennies? What about other US coins?
GENERATE IDEAS
* Students will research independently the chemicals found in US coins and how they can oxidize and reduce.
* Students will investigate how to assemble a voltaic cell and learn how it works.
* Students will investigate the effect of sodium chloride (electrolyte) in oxidation-reduction reactions.
MULTIPLE PERSPECTIVES
Students will discuss their ideas through brain storming before performing experiments.
RESEARCH & REVISE
Once data is collected, students will discuss their results and draw conclusions.
TEST YOUR METTLE
Students will compare their results against their peers’ observations and conclusions.
GO PUBLIC
Students will discuss among themselves and in front of the class their results.

## Test Your Mettle Quiz

True or False (50 points)
1.- Gold is used in the US American gold eagle
2.- Gold is used in the US American platinum eagle
3.- Silver is used in some US coins
4.- Copper is among the most common metals used in US coins
5.- Zinc is not found in US coins
6.- Nickel is the major component in 5 cents coins
7.- A voltaic cell is also called a galvanic cell
8.- A voltaic cell can generate electricity through chemical reactions
9.- A reduction - oxidation reaction takes place in a voltaic cell
10.- Electrochemistry is the branch of chemistry that deals with the interconversion of electrical energy and chemical energy
Multiple choice (50 points)
11.- A redox reaction will have:
    a) Electrons being transferred from one substance to another
    b) Electrons are not transferred
    c) Electrons do not participate in this type of reaction
    d) None of the above
    e) More than one of the above
12.- If a compound loses electrons it is:
    a) Reduced
    b) Oxidized
    c) Its oxidation state remains the same
    d) More than one of the above
    e) None of the above
13.- What is an electrode?
    a) Metals found in galvanic cells
    b) Non metals acting as insulators in galvanic cells
    c) Metals where oxidation reactions occur
    d) Metals where reduction reactions occur
    e) More than one of the above
14.- A voltaic cell will generate electricity from a chemical reaction only if:
    a) The metals used in the electrodes are different
    b) The metals used in the electrodes are the same
    c) The electrodes provide for an overall reaction that contains an oxidized and a reduced species
    d) None of the above
    e) More than one of the above
15.- The best method to prepare a voltaic cell is by:
    a) Placing adjacent electrodes containing the same metal
    b) Placing adjacent electrodes containing different metal (alternating them)
    c) Either assembly should work appropriately