====== Elephant's Toothpaste ====== **Materials: **{{$demo.materials_description}} \\ **Difficulty: **{{$demo.difficulty_description}}\\ **Safety: **{{$demo.safety_description}}\\ **Categories:** {{$demo.categories}} **Alternative titles:** Peroxide Whoosh ====Summary==== {{$demo.summary}} ====Procedure==== A small teaspoon of solid Potassium Iodide, a squirt of detergent, and a few drops of food colouring are put into a measuring cylinder of any size placed into a tray. 30% Hydrogen Peroxide is added, and coloured foam is formed rapidly, spurting out of the top. ====Links==== 📄 With 3% Hydrogen Peroxide and yeast catalyst: [[https://www.sciencebuddies.org/stem-activities/elephant-toothpaste]]\\ 📄 With 30% Hydrogen Peroxide and Potassium Iodide catalyst: [[https://www.thoughtco.com/elephant-toothpaste-chemistry-demonstration-604250]]\\ 🎞️ A very large example in a swimming pool: [[https://www.youtube.com/watch?v=Kou7ur5xt_4]]\\ 🎞️ World's Tallest: [[https://www.youtube.com/watch?v=e09xig209cQ]]\\ {{youtube>Z6i1IDuWUDc?}}\\ ====Variations==== * Using 3 or 6% Hydrogen Peroxide will make the foam form much slower, but it will still overflow the measuring cylinder. * Using a conical flask instead of measuring cylinder can make the foam shoot higher, and it can reach the roof. * Putting a glowing splint into the foam afterwards can make it glow brighter, but the foam also helps to extinguish it so it probably can't be made to relight. ====Precautions==== * Safety glasses required\\ * Student should stand back at least 1 metre\\ * Gloves may be worn\\ ====Questions to consider==== * What is the reaction occurring? * What gas is produced? * What is the evidence of a gas being produced? * What is the evidence of a chemical change? * How does the concentration of the Hydrogen Peroxide affect the reaction rate? ====Further Investigation==== * Compare the reaction rate with several different concentrations of Hydrogen Peroxide. * Compare the reaction rate between using a sold Potassium Iodide, aqueous Potassium Iodide, or Yeast catalyst. * Use different colours of food colouring, or a different colour on each side of the measuring cylinder.