Materials: |
- A piece of clear Tygon tubing held in a U-shape by ring
stands and clamps
- A solution of Universal Indicator in water
- A solution of a weak acid (such as vinegar)
- A solution of a weak base (such as baking soda)
|
Procedure:
- Fill the Tygon tubing with a solution of Universal Indicator in water.
- Into one open end of the Tygon tubing a weak acid (such as vinegar) is added by a pipette and into the other end a weak base (such as a baking soda solution) is added by a pipette.
- The Tygon tubing can be gently shaken so that the materials slowly mix. This will lead to interesting color changes but will eventually even out in color.
- Allow for discussion.
This can be repeated many times with out change materials. As the tube fills a little can be siphoned off and discarded.
----Contributed by Frank Salter, Mark Twain Section