Decomposition Reaction: Oxygenated Water Decomposition

4.4/5 - (69 votes)

EXPERIMENT SHEET

Theme Chemical Reactions
Category Scientific Experiments, Chemistry Experiments
Main products Hydrogen Peroxide, or hydrogen peroxide. Potassium iodide
Short description In this reaction we will be able to see the decomposition of hydrogen peroxide, H2O2 into H2O and O2. To make it a fast reaction, we add a catalyst, potassium iodide, which will accelerate the reaction.

 

MATERIALS DECOMPOSITION EXPERIMENT OXYGENATED WATER

  • Oxygenated water. Oxygenated water at 30% or 110 volumes. Sold in some drugstores.
  • Potassium iodide. Potassium iodide will speed up the decomposition reaction making it more attractive. Potassium iodide can be found at Alquera.com

STEP-BY-STEP EXPERIMENT

    1. Put the hydrogen peroxide in a glass container. We have used a erlenmeyer flask 1000ml but any other glass container will do.

      DESCOMPOSICIÓN AGUA OXIGENADA
      OXYGENATED WATER
    2. Add 1/3 teaspoon of potassium iodide (about 1-2 grams).

      WE ADDED POTASSIUM IODIDE
    3. The reaction starts slowly

      COMIENZA LA REACCIÓN
      THE REACTION BEGINS
    4. Gradually, the reaction becomes more and more accelerated, even violent, and all the O2 is released from the hydrogen peroxide H2O2.

      REACCIÓN
      REACTION GETS VIOLENT

 ON VIDEO

 

TECHNICAL EXPLANATION

Naturally oxygenated water, H2O2, decomposes according to the chemical reaction:

2H2O2(aq) → O2 + 2H2O(l)

It is a process, although not slow, not instantaneous. By adding potassium iodide what we achieve is to catalyse this decomposition according to the following reactions. The reaction is strongly exothermic, as it proceeds this generates heat, which in turn helps the decomposition.

H2O2(aq) + I-(aq) → OI-(aq) + H2O(l)
H2O2(aq) + OI-(aq) → I-(aq) + H2O(l) + O2(g)

Leave a Reply

Your email address will not be published. Required fields are marked *

en_GBEnglish