Summary: Students will use a pH indicator solution to detect the presence of carbon dioxide and changes in acidity, and to model ocean-atmosphere interactions.
Source: Adapted by NESTA/Windows to the Universe team members Missy Holzer, Jennifer Bergman, and Roberta Johnson from the Carbon Dioxide Sources and Sinks activity on Windows to the Universe.
Time: This activity requires careful preparation including some set-up the previous day. It is recommended that the directions be read carefully before beginning this activity.
- Materials preparation: 40 minutes
- Class time: 40 minutes
- Discussion and review: 30 minutes
Student Learning Outcomes:
- Students will be able to explain the concept of ‘sources’ and ‘sinks’ as they relate to carbon dioxide.
- Students will understand the use of an indicator solution (BTB) to reveal the presence of carbon dioxide as well as levels of acidity.
- Students explain the cause and effect relationship between lower pH levels of seawater and carbonate ion availability for shell formation in marine organisms.
Lesson format: Laboratory Experiment
National Standards Addressed:
- National Science Content Standards 5-12: Abilities necessary to do scientific inquiry
- National Science Content Standard 5-8: Properties of Earth materials
- National Science Content Standards 9-12: Geochemical Cycles
- National Science Content Standards 9-12: Environmental Quality
Materials:
For each four-student team
- Five test tubes
- Test tube rack
- One hole stopper with tubing attached
- Baking soda
- Vinegar
- Aluminum foil
- Cotton balls
- Bottle of BTB solution (bromothymol blue)
- Straws
- Sprig of Elodea (available in pet stores)
- Masking tape
- Markers
- Distilled water
- 250 mL beaker or plastic cup
- graduated cylinder
- coral and shell specimens
- pH indicator solution (from an aquarium test kit)
…
Missy Holzer, Windows to the Universe, 3 March 2011. More information.
