Catalytic Decomposition of H2O2 – Elephant’s Toothpaste Experiment
Description:
H2O2 is
decomposed by Iodide Ion. Iodide ion is used as a catalyst and these iodide
ions come from KI (Potassium Iodide) or NaI (Sodium Iodide). This decomposition
reaction liberates water, oxygen and heat.
Materials:
30% H2O2
(Hydrogen Peroxide)
1 Liter Graduated cylinder
KI (Potassium Iodide) or NaI (Sodium
Iodide).
Food Color for fun
Liquid Dish Detergent
Procedure:
1.
Pour 50 mL of 30% H2O2
(Hydrogen Peroxide) in 1 L graduated cylinder.
2.
Then, add 3-4 drops of food color in
1 L graduated cylinder to make colored H2O2 solution.
3.
Then, start adding liquid dish
detergent or soap from the side of 1 L graduated cylinder to make a small layer
of liquid dish detergent or soap over colored H2O2
solution.
4.
With the help of small beaker add KI
or NaI in the cylinder containing H2O2 solution. As a
result of reaction, oxygen gas generated and this gas creates large amount of
colored foam. This foam comes out of graduated cylinder.
Discussion:
Decomposition of H2O2
(Hydrogen Peroxide) yields O2 (oxygen) and H2O (water). Reaction
is catalyzed by I- (Iodide Ion); These Iodide Ion comes from KI or
NaI
Reaction-
H2O2 (Aq) + I-1
(Aq) ---> H2O (liquid) + IO- (Aq)
IO- (Aq) + H2O2
(Aq) ---> H2O (liquid) +O2 (g) + I-
(Aq)
Overall Reaction-
2H2O2 (Aq)
---> 2H2O (liquid) +O2 (g)
Safety:
Wear proper protective equipment likes hand-gloves and safety goggles when preparing and demonstrating this experiment. Remember concentrated H2O2 (Hydrogen Peroxide) can cause burns.Video of Catalytic Decomposition of H2O2 – Elephant’s Toothpaste Experiment:
