Elephant Toothpaste

Dish soap is placed in large flask with 20 mL of 30% hydrogen peroxide. Two different colours of food colouring are dribbled down the neck of the flask. Add 5 g KI (POTASSIUM IODIDE) powder and step back. (30% hydrogen peroxide and potassium iodide cannot be bought in local stores - google to find out where to buy) The exothermic reaction produces heat and oxygen gas and a lot of foam. Plunge a glowing splint into the foam. The pure oxygen will cause it to relight until it gets too wet. This activity is excellent for discussions about catalysts, exothermic reactions and decomposition reactions. 2H2O2 = 2H20 + O2. dupuis.shawbiz.ca