Red Cabbage Chemistry
Students take advantage of the natural ability of red cabbage juice to perform as a pH indicator to test the pH of seven common household liquids. Then they evaluate the accuracy of the red cabbage indicator, by testing the pH of the liquids using an engineer-designed tool, pH indicator strips. Like environmental engineers working on water remediation or water treatment projects, understanding the chemical properties (including pH) of contaminants is important for safeguarding the health of environmental water sources and systems.
Red cabbage juice is a natural indicator for measuring the pH of solutions.Copyright State of Tennessee http://news.tn.gov/node/8756
An important consideration for environmental and chemical engineers is pH. The pH of different liquids and solutions, particularly the pH of bodies of water, are important in describing the behavior of different minerals and chemicals. For example, with increasing acidic pH values, water begins to cause harm and destruction of ecosystems and minerals, such as dissolving the calcium carbonate shells of mollusks, or making ecosystems unlivable for plants and animals.
After this activity, students should be able to:
- Define acidity and basicity and how they relate to different liquids.
- Relate the importance of pH to environmental systems such as lakes, rivers and oceans, as well as environmental engineering concerns.
- Explain how pH, acids and bases are important factors in natural systems, such as the human body.