Decomposition of Hydrogen Peroxide

This is a set up for Decomposition of Hydrogen Peroxide. H2O2. The yellow hexagon shape you see is an inverted graduated cylinder. It is filled with water. You may have played with a similar set up as a kid in a bath tub. If you invert a container in water, it does not lose any water in the cylinder. A syringe is filled with 3 ml of KI (Potassium Iodine. The tube is then inserted into the cylinder. The Erlenmeyer flask has a rubber stopper so it is air tight. One the syringe is injected into the flask that is filled with air, the reaction cause a release of gas which then travels through the tube and into the graduated cylinder. The gas displaces the water from the cylinder into the container.