Viewing a Chemical Change

Part of the "Chemistry in the Kitchen" Collection

Goal

Students will view a chemical change with Red Cabbage Chemistry.

Estimated Time

45 Minutes

Setting Required

Inside

Standards

  • S5P1. Obtain, evaluate, and communicate information to explain the differences between a physical change and a chemical change.
    • a. Plan and carry out investigations by manipulating, separating and mixing dry and liquid materials and communicate collected data to demonstrate examples of physical change.
    • b. Construct an argument based on observations that the physical changes in the state of water are due to temperature differences, which cause small particles that cannot be seen to move differently.
    • c. Plan and carry out an investigation to determine if a chemical change occurred based on observable evidence (color, gas, temperature change, odor, new substance produced)

Materials

  • Red cabbage
  • Blender
  • Strainer
  • Clear drinking glasses
  • Water
  • Test chemicals: vinegar, baking soda, lemon juice, washing soda, laundry detergent, soda pop, Alka-Seltzer
  • Red Cabbage Chemistry¬†from Steve Spangler Science

Procedures

  1. Explain to students that pH is the measure of the concentration of H30+ ions in water. When an acid or a base is added to the water it affects the concentration of those ions and can be seen visually through a change of color.
  2. Complete the Red Cabbage Chemistry activity as a whole group to see the chemical change
  3. For another experiment, visit http://www.explorit.org/news/starchy-potato-chemistry