Elephant Toothpaste MV WiSTEM 9/28
Materials 1) 1/2 cup 20-volume hydrogen peroxide liquid (20-volume is a 6% solution, which can be found at a beauty supply store or hair salon)2) 3 Tablespoons of warm water3) Liquid dish washing soap4) Food coloring 5) 1 Tablespoon Yeast
Procedure:1. Put on gloves and goggles. The concentrated hydrogen peroxide usedin this experiment will burn the skin and eyes. It can also bleachfabric, so choose your clothing with that in mind.2. Pour hydrogen peroxide into the bottle. Using a funnel might help.3. Add 8-10 drops of food coloring into the bottle.4. Add about 1 tablespoon of liquid dish soap into the bottle and mixthe solution by swishing it around.5. Mix the warm water and the yeast in a separate small cup for about30 seconds. This activates the yeast.6. Mix with a spoon for 30 seconds, then remove any large lumps.7. Pour the yeast mixture into the bottle and stand back!
Science behind it: Elephant Toothpaste Chemistry:The overall equation for this reaction is:2 H2O2(aq) --> 2 H2O(l) + O2(g)However, the decomposition of the hydrogen peroxide into water andoxygen is catalzyed by the iodide ion.H2O2(aq) + I-(aq) --> OI-(aq) + H2O(l)H2O2(aq) + OI-(aq) --> I-(aq) + H2O(l) + O2(g)
More Science! • The dishwashing detergent captures the oxygen as bubbles. Foodcoloring can color the foam. The heat from this exothermic reaction issuch that the foam may steam. If the demonstration is performed usinga plastic bottle, you can expect slight distortion of the bottle fromthe heat. You might remember Mom treating your scraped knee or a cut withhydrogen peroxide. H2O2 is the scientific name for hydrogen peroxide which is made up oftwo hydrogen atoms and two oxygen atoms. H2O2 looks like ordinarywater (H2O), but the addition of that extra oxygen atom turns themolecule into an extremely powerful oxidizer. The hydrogen peroxidefound at the grocery store is a low grade 3% solution which is safe totouch but powerful enough to kill bacteria, viruses, and fungi onsurfaces.
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