What is the reaction between hydrogen peroxide and iodide?

How would hydrogen peroxide and iodide ions in acid solution react with ammonium molybdate as a catalyst ?
Trystan Voaden

The reaction is

H₂O₂(aq) + 3I^-(aq) + 2 H⁺(aq) I₃^-(aq) + 2 H₂O(aq)

The reaction above is often very slow, so a catalyst is usually added. Ammonium molybdate works; so do other transition metal ions. The catalytic action probably involves a free radical mechanism. Hydrogen peroxide can reduce MnO₄^-, but molybdate isn't a strong enough oxidizing agent to be reduced.

Author: Fred Senese senese@antoine.frostburg.edu

Copyright © 1997-2001 by Fred Senese
Comments & questions to senese@antoine.frostburg.edu
Last Revised 02/23/18.URL: http://antoine.frostburg.edu/chem/senese/101-hidden/redox/faq/h2o2-iodide-reaction.shtml