Old Foamy

Introduction:

My project name is called Old Foamy and it is also called "Elephant Toothpaste". The Old Foamy demo is exothermic chemical reaction.

Materials:

• 50-100ml of 30% hydrogen peroxide (H2O2) solution

• Saturated Potassium Iodide (KI) solution

• Liquid Dishwashing Detergent

• Food Coloring (optional)

• 500 mL graduated cylinder

Procedures:

1. Put on gloves and safety googles. The iodine may leave a stain in the surface of your work table so make sure to put paper towels or garbage bags.

2. Pour 50 mL of 30% hydrogen peroxide solution into the graduated cylinder (although in our experiment we doubled every solution for fun.)

1. Squirt a little of dishwashing detergent and swirl around

1. (Optional, If you don't want to skip this step and proceed to next step) Place 5-10 drops of food coloring into cylinder to change color.

2. Add 10 mL of potassium iodide solution. Warning: do not lean over cylinder when this happens, the reaction will react quickly and you may get splashed.

3. Record observations if needed

Scientific Principle:

The Overall equation for this reaction is:

2H2O29(aq) + I(aq) = OI(aq) + O2(g)

However, the decomposition of the hydrogen peroxide into the water and oxygen is catalyzed by the iodide ion.

H2O2(aq) + I(aq) = OI(aq) + H2O(I)

H2O2(aq) + OI(aq) = I(aq) + H2O(I) + O2(g)

The dishwashing detergent captures the oxygen as bubbles. Food coloring can color the foam. The heat from this exothermic reaction is such that the foam may steam. If the demonstration is performed using a plastic bottle, you can expect a slight distortion of the bottle from the heat.

Safety Regulations:

Wear disposable gloves and safety glasses. Oxygen is evolved in this reaction, so do not perform this demo near an open flame. Also, the reaction is exothermic, producing a fair amount of heat, so do not lean over cylinder when the solutions are mixed. Leave gloves on for cleanup of demo. The solution and foam may be rinsed down the drain with water