Demonstrate simple electrolysis in a very colorful and dramatic way on your overhead projector. A 9V battery supplies the power and universal indicator provides the color show. As electrolysis occurs in the Petri dish, the pH changes at the anode and cathode are different. The solution around the cathode immediately turns purple as hydrogen gas bubbles are formed. At the anode, oxygen is produced and the solution turns orange/red in color. Across the entire Petri dish the entire spectrum of universal color changes occur reflecting the pH continuum created in the Petri dish. Teacher Demonstration Notes are included.