Laboratory Preparation of Oxygen gas from Hydrogen Peroxide

To prepare oxygen in a lab, start with a flat-bottom flask fitted with a two-hole stopper. One hole should have a thistle funnel, while the other should have a delivery tube leading to a trough with a beehive shelf. Fill a gas jar with water since oxygen will be collected by displacing this water downwards. Add manganese dioxide MnO2, a black powder, to the flask. This acts as a catalyst, speeding up the reaction without being consumed. Then, pour hydrogen peroxide into the flask through the thistle funnel. The reaction will be slower because the peroxide is dilute. Watch for bubbles in the flask as a sign that the reaction has started. Initially, allow some air to escape from the delivery tube. Then, place the gas jar over the beehive shelf to collect the oxygen. The flask will warm up due to the exothermic nature of the reaction. To test for oxygen, fill a test tube with the gas from the jar. Use a glowing splint; if it reignites in the test tube, oxygen is confirmed. For another demonstration, burn sulfur in oxygen. The sulfur will burn with a brighter, blue flame compared to when its in air. To demonstrate the acidity of sulfur dioxide, burn sulfur in oxygen to produce it. Place blue litmus paper in the jar. If the paper turns red, it indicates sulfur dioxides acidity, forming sulfurous acid when dissolved in water. Allow sufficient time for the gas jar to fill, and seal it once collection is complete to retain the oxygen. Always confirm oxygens presence using the glowing splint test.