Blinking Holiday Colors - Chemical Demonstration Kit
By: The Flinn Staff
Item #: AP6858
The Blinking Holiday Colors Chemical Demonstration Kit is sure to grab the attention of your students. Certainly this demonstration will prompt a review of buffers and pH indicators in this red and green clock reaction.
This item can only be shipped to schools, museums and science centers
Two solutions of holiday red and green are poured into separate tall form beakers and stirred. After 30 seconds, the beakers magically swap colors, red to green and green to red! Each solution contains a unique mixture of indicators. At low pH, one mixture is red, the other green. At high pH, the red indicator turns green and the green switches to red. The key to the blinking holiday colors is a clock reaction. Each solution starts out slightly acidic and buffered. When one reactant is completely consumed, the pH rapidly increases and the holiday colors rapidly reverse. Holiday fun at an excellent price! Enough materials are included to perform the demonstration seven times.
Concepts: Buffers, pH indicators, clock reactions.
Time Required: 10 minutes
Materials Provided: Formaldehyde solution, sodium sulfite, sodium bisulfite, green-to-red indicator solution, red-to-green indicator solution.