By: Penney Sconzo, Westminster Academy, Atlanta, GA
Item #: AP6433
The Organic Rainbow Chemical Demonstration Kit uses universal indicator to vividly display a hydrolysis reaction. The hydrolysis reaction gradually increases the pH to display the rainbow colors of universal indicator.
This item can only be shipped to schools, museums and science centers
Add a clear liquid to a red solution and watch as the colors of the rainbow appear in sequence. But wait, there’s more! After a few seconds, the colors of the solution mysteriously reverse directions—switching from violet to blue, green, yellow, orange and finally back to red. Add more clear liquid and the color cycle repeats. This demonstration uses universal indicator to vividly display the hydrolysis reaction of tert-butyl chloride. The hydrolysis reaction produces acid that is slowly consumed by the clear base solution—gradually increasing the pH to display the rainbow colors of universal indicator. Once the base is fully depleted, acid concentration builds up again, thereby reversing the color change back to red. A detailed worksheet is provided for students to record their observations and form conclusions about the reaction they are viewing. Teacher Demonstration Notes included.
Concepts: Organic chemistry, hydrolysis, indicators. Time Required: 15 minutes Materials Provided: Acetone, tert-butyl chloride, universal indicator, sodium hydroxide solution, Beral-type pipets. Note: A 500-mL graduated cylinder or hydrometer cylinder is required and available separately.