- Grade level: Upper or Lower Elementary
- Subject Area: Science, Language Arts
Students conducting the following experiment will learn about acids and bases by creating a solution to test for them and by using the Web to ask questions of scientists and/or to conduct Web-based research. Students can collaborate with students at other schools either by conducting the experiment simultaneously over CU-See Me or by exchanging data, information, and observations over email.
- Students will use the scientific method to collect data.
- Students will gain experience communicating scientific data.
- Students will enhance their writing abilities by corresponding with an online scientist and sharing data with students at other schools.
Materials and Resources
- Hardware requirements: computer and modem.
- Software requirements: email and/or CU-See Me, Web browser (preferably Netscape)
- Network/Internet requirements: Access to the Internet
- Chopped red cabbage
- Two glasses
- Cooking pot
- Baking soda
- Make cabbage water by heating the chopped cabbage and two cups of water in the pot for ten minutes, until the water is dark purple. Strain the cabbage over the bowl and save the cabbage water for the experiment.
- Find a scientist who would be willing to field questions from students about acids and bases, either synchronously over CU-See Me or asynchronously over email. Consult this site for suggestions on contacting scientists, or contact a scientist in your area who would be willing to correspond with students.
- Find a class at another school that would be willing to exchange data, either synchronously over CU-See Me or asynchronously over email. Consult this site for suggestions on contacting interested schools, or pair up with a school in the same or a nearby district.
- Add a tablespoon of cabbage water to a glass containing a tablespoon of lemon juice.
- Add a tablespoon of cabbage water to a glass containing a tablespoon of baking soda.
- Record your observations.
- Add cabbage water to other types of foods, such as fruit juice, egg white, or vinegar. Record these observations. Discuss with students which kinds of foods turn the cabbage water certain colors. What else do foods that turn the water the same color have in common with each other? Have they heard of any natural phenomena having to do with acids or bases (ie: acid rain)?
- Share data with students from another school over email and/or CU-See Me. Compare types of food tested and experimental results.
- Pose questions to a scientist about this experiment over email and/or CU-See Me. Conduct background research about the potential relevance to our lives of knowing about pH levels. Use the resources below and directed Internet searches.
- Activities/Information on pH
This is the result of a search of the Explorer database. Contains downloadable ClarisWorks documents on pH activities.
[gopher://ec.sdcs.k12.ca.us:70/00/lessons/UCSD_InternNet_Lessons/ Physical_Science_and_Chemistry/Chemical_Reactions/ Cabbage_Juice_pH_Magic.txt]
Gopher site providing a little background information on chemical indicators.
- You Can & Acid Rain
Another take on the acid indicator activity, this time in the context of acid rain.
- EcoNet's Acid Rain Resources
General information on acid rain.