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Disappearing Rainbow - Chemical Demonstration Kit

By: The Flinn Staff

Item #: AP8979

Price: $37.75

The Disappearing Rainbow Demonstration Kit is popular among students and teachers alike. Two colorless solutions are added to seemingly empty beakers, creating a rainbow of colors. Students are amazed when the rainbow then disappears.

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This item can only be shipped to schools, museums and science centers

Product Details

Your students will love this colorful demonstration which is always a teacher favorite at science conventions. A colorless solution is added to each of six seemingly empty beakers. A second colorless solution is then added and each of the six resulting solutions turns a different color of the rainbow. Add more of the first solution and the rainbow of colors disappears. Challenge your students to explain these amazing observations. The secret is the small amount of indicator or mixture of indicators placed in each beaker before the demonstration. The first solution is hydrochloric acid which keeps the indicators colorless. The second solution is sodium hydroxide which raises the pH and activates the indicators causing a spectrum of color to appear. Enough materials are included to perform the demonstration seven times. Concepts: Acid-base indicators. Time Required: 15 minutes Chemicals Provided: Sodium hydroxide solution, hydrochloric acid solution, indicator solutions of violet, blue, green, yellow, orange, and red.