Generation of oxygen




	Generation of oxygen
	Oxygen is generated in a plastic pipette. Materials Test tube that fits to a single stand, single stand, plastic pipette, 5 mL syringe, hypodermic needle (0.8 mm/40 mm), isolation tape, cutting pliers, a pair of scissors or scalpel and tweezers. Chemicals 4 mL 5 % H₂O₂, one grain of 1:1 cement with MnO2 (according to Prof. Victor Obendrauf) Safety tips Wear safety goggles! Syringe needle’s tip is sharp! You must be careful while piercing the pipette’s bulb. Always use syringe needles with wide diameter (0.8 mm -1.2 mm) in order to avoid case of clogging when there is possible reaction of reagent with the needle metal.
	Procedure Cut the pipette’s stem to make it shorter; Make a section to pipette’s bulb; Insert a needle into the pipette’s bulb; Take the tip of the needle out of the bulb trough the section and cut the tip with pliers; Insert the grain of cement with MnO₂ in the pipette’s bulb and close the section with isolation tape or sticky tape; Place the test tube on the stand and fill it with 5 % H₂O₂; Connect the syringe with the needle; The apparatuses should be assembled as it shown on. Fill the pipette’s bulb with the H₂O₂ solution from the test tube by bending the stem.	Fig. 1. Pipette’s bulb with the cathalist
	During this, the needle and the syringe should stay connected on the pipette’s bulb; The H₂O₂ in contact with MnO₂ will generate oxygen which will be collected in the pipette’s bulb;