Activity 3.2 - Observing Soda Water Fizzing (30 min)

Target Student Performance

Students record data about changes in mass and BTB when soda water fizzes and reach consensus about patterns in their data.

Resources You Provide

  • BTB, blue (less than 1 cup per group of four students)
  • digital balance (1 per group of four students)
  • Petri dish, plastic (2 per group of four students)
  • sealable, 9.5-Cup container (1 per group of four students)
  • soda water (less than 1 cup per group of four students)
  • (Optional) Molecular modeling kits
  • (From previous activity) 3.1 Predictions and Planning Tool for Soda Water Fizzing

Resources Provided

Recurring Resources


Prepare the BTB (see instructions in the BTB Information and Instructions Handout), Petri dishes, soda water, digital balances, plastic containers, and safety glasses for students to retrieve for their groups. If you plan to use the poster to record student data, print one copy of the poster before class and post it on the wall. Print one copy of 3.2 Observing Soda Water Fizzing Worksheet for each pair of students. Prepare a computer with an overhead projector to display the PPT. Optionally, print one copy of the BTB Color Handout for each group.


1. Use the instructional model to show students where they are in the course of the unit.

Show Slide 2 of the 3.2 Observing Soda Water PPT.


Have students develop the experimental design on their own using the tools provided. For example, students may choose to set up a control treatment as a chamber with BTB and no soda water.


Addressing problems at this point as students try to find patterns in data will support their learning in future investigations. This is the first investigation, so it is likely to expose challenges that may come up again.

Extending the Learning

Students may want to compare what happens with soda water fizzing with other conditions, such as seeing what happens to mass and BTB with plain water in the Petri dish, or how their observations are affected by the amount or temperature of the soda water.