Chemical demonstration

The serpent

A great demonstration of the action of an inorganic catalyst on the rate of a chemical reaction is the "Serpent".
The ingredients for the serpent demonstration.

To conduct this activity you will need a:

- pneumatic trough

- Potassium iodide crystals

- 33% hydrogen peroxide

- Dishwashing liquid

- Green food dye.

- 100ml measuring cylinder

Place 20ml of hydrogen peroxide solution in the measuring cylinder. Add detergent (about 6 ml) and a few drops of green food dye. Place the mesuring cylinder in the trough and add a small spatula full of KI crystals.


The demonstration shows vividly the increase in the rate of the reaction represented by the equation


Look at the chemical reaction.

Is this reaction exothermic or endothermic?
Do the products contain more energy than the reactants?