Basically Acids
Using red cabbage juice as a pH indicator.Copyright 2010 Rachel Howser, GK-12 Program, University of Houston
Students use the associated activity to learn the basics of acid/base chemistry in a fun, interactive way by studying instances of acid/base chemistry found in popular films such as Harry Potter and the Prisoner of Azkaban and National Treasure. Students learn what acids, bases and indicators are and how they can be used, including invisible ink. They also learn how engineers use acids and bases every day to better our quality of life. Students' interest is piqued by the use of popular culture in the classroom.
Acid/base chemistry is a pervasive scientific concept used across many engineering disciplines. Engineers use their knowledge of acids and bases to design non-corrosive material combinations, car batteries, chemical fertilizers and food preservation techniques. Writing with invisible ink that can be read using an acid/base indicator was commonly employed by engineers, inventors and military leaders during the American Revolutionary War to communicate secret messages.
After this lesson, students should be able to:
- Hypothesize whether a liquid is an acid or a base.
- Identify whether a liquid is an acid or base based on its color interaction with cabbage juice.
- Explain how acids and bases were used during the American Revolution to send spy letters.
- Describe how engineers use acids and bases.