Q260: Chemiluminescence – Luminol (Firefly reaction)

Introduction

Two solutions are combined in a darkened room, producing luminescence that lasts for several seconds. 

Peroxides act as an oxidizing agent.  The luminol is converted to an excited-state product.  This product decays to the ground state while emitting light.  Luminol is 3-aminophthalhydrazide.

Peroxide acts as an oxidizing agent.  The luminol is converted to an excited-state product.  This product decays to the ground state while emitting light. 

To Conduct Demonstration

  1. Position a beaker at the bottom of the spiral tube to collect the solution.
  2. Turn the lights down or off in the classroom.
  3. Pour equal amounts of solutions A and B simultaneously into the funnel at the top of the spiral tube.
  4. OPTIONAL: Activate variously colored light sticks. 

Reaction Time: Leave for the rest of the class period

Safety 

Safety: Eye protection should be worn.

References

L.R. Summerlin and J.L. Ealy Jr., Chemical Demonstrations: A Sourcebook for Teachers, 1985.
Chemistry in the Classroom (pamphlet distributed by Kodak).

Acknowledgment

John Ohlsson, Spring 1987