Science - Chemistry
Standard 4 Objective 2
1 class periods of 90 minutes each
With this inquiry experiment students will design their own batteries and learn about why batteries work.
10-15 min. introduction, 50 minutes for experiment, 20 minutes for follow-up discussion and for students to do questions.
"Oxidation" and "reduction" reactions make a battery work. Oxidation/reduction reactions are electron-transfer reactions. For a battery to work, both an oxidation and a reduction must happen. One generates electrons at one electrode, and the other uses them up at the other electrode. Each of these is called a "half reaction". If the electrodes are connected outside the cell by a circuit, electrons flow and the full reaction is completed.
Oxidation is when electrons are transferred from a substance to oxygen or some other compound. Oxidation doesn't have to involve oxygen, and can be thought of as "de-electronation." Since electrons are negatively charged particles they are related to electricity. Electrons moving along a conductor is electric current. The electrode where oxidation (loss of electrons) takes place is called the anode. On a commercial battery it is marked as the "-" side.
For information on the reasons some combinations of metals and electrolytes are better than others in real batteries see: http://antoine.frostburg.edu/chem/senese/101/redox/faq/choosing-battery-reactions.shtml
Lesson Design by Jordan School District Teachers and Staff.