If you like us, please share us on social media.
The latest UCD Hyperlibrary newsletter is now complete, check it out.

ChemWiki: The Dynamic Chemistry E-textbook > Development Details > Approaches > Demos > Additional Demos > The Chemiluminescent Clock Reaction

Copyright (c) 2006-2014 MindTouch Inc.

This file and accompanying files are licensed under the MindTouch Master Subscription Agreement (MSA).

At any time, you shall not, directly or indirectly: (i) sublicense, resell, rent, lease, distribute, market, commercialize or otherwise transfer rights or usage to: (a) the Software, (b) any modified version or derivative work of the Software created by you or for you, or (c) MindTouch Open Source (which includes all non-supported versions of MindTouch-developed software), for any purpose including timesharing or service bureau purposes; (ii) remove or alter any copyright, trademark or proprietary notice in the Software; (iii) transfer, use or export the Software in violation of any applicable laws or regulations of any government or governmental agency; (iv) use or run on any of your hardware, or have deployed for use, any production version of MindTouch Open Source; (v) use any of the Support Services, Error corrections, Updates or Upgrades, for the MindTouch Open Source software or for any Server for which Support Services are not then purchased as provided hereunder; or (vi) reverse engineer, decompile or modify any encrypted or encoded portion of the Software.

A complete copy of the MSA is available at http://www.mindtouch.com/msa

The Chemiluminescent Clock Reaction


Chemical Concepts Demonstrated

  • Chemiluminescence
  • Chemical kinetics


The 4 beakers contain 4 solutions in varying amounts. The solutions are poured into the beakers simultaneously.
  • Solution A: Luminol dissolved in NH3 and diluted.
  • Solution B: K3Cu(CN)4 dissolved in water
  • H2O2
  • water

All the beakers contain the same amount of Solutions A and B.  Beaker 4 contains the least amount of H2O2 and the most water, beaker 1 contains the least amount of water and the most H2O2, and the remaining two beakers have amounts in a relative series to these two.



The four beakers begin to glow in a specific order.


The mechanism for this reaction is not well known.  However, it is believed that it involves the oxidation of the Cu(CN)43- complex ion to Cu2+, which then forms an amine complex that catalyzes the oxidation of luminol by hydrogen peroxide.

Despite the uncertainties regarding the mechanism, this demonstration is still useful for qualitative analyses of chemical kinetics and chemiluminescence.



You must to post a comment.
Last modified
10:30, 2 Oct 2013



(not set)
(not set)

Creative Commons License Unless otherwise noted, content in the UC Davis ChemWiki is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. Permissions beyond the scope of this license may be available at copyright@ucdavis.edu. Questions and concerns can be directed toward Prof. Delmar Larsen (dlarsen@ucdavis.edu), Founder and Director. Terms of Use