The Battery Boom
Americans spend about 2.5 billion dollars a year on batteries to feed the electrical appetites of all kinds of electronic devices from boom boxes to cell phones. A battery is a voltaic cell designed to convert chemical energy to electricity. Batteries work on the principles of oxidation-reduction reactions you learned about in Chapter 22. A redox reaction is a chemical reaction in which electrons transfer from one reactant to another. Batteries are engineered to convert this electron transfer into a useful electrical current.
As an example, a common alkaline battery contains zinc and manganese dioxide. They react in a basic medium according to the following half reactions.
Oxidation:
ZnZn2+ + 2e–
Reduction:
2MnO2 + 2H2O + 2e–
As the electrons flow from zinc to manganese dioxide, they pass through an electrical circuit and power an electrical device.
In this Internet activity, you will test your knowledge of batteries and learn some of the chemistry of batteries. Read about the science and history of batteries given at the Duracell Frequently Asked Questions site.
Check your answers at the bottom of the quiz and read the information provided.
Additional Activities
- How Batteries Work is an excellent article that includes many suggestions for simple experiments you can do at home.
- View an animated demonstration at the Duracell Frequently Asked Questions site. Click on the link, "How does a battery work?" Write the chemical reactions for the positive and negative electrodes and the overall reaction.