Summary Collect gases (oxygen and carbon dioxide) over water, then show how to test them with a glowing/lighted splint. Science content Chemistry: States of Matter, Properties of Materials (K-7) Chemistry: Chemical Changes (2, 7) Materials tray filled with water water glass bottle filled with water reaction bottle with tube attached to lid reactants: H2O2 and yeast to make oxygen; baking soda and vinegar to make CO2 splint lighter Procedure Collect oxygen over water. Relight a glowing splint by lowering it into the tube of oxygen. Feel the exothermic reaction. Collect CO2 over water - puts out a lighted splint. Notes Developed for The Chemistry of Gases and Pressure lesson methane ignites - stir up from the bottom a pond. not toxic. when collects stays in the tube as lighter than air