c CATAL YSTS AND RATE OF REACTION The variable in this reaction is the substance used as a catalyst in the decomposition of an aqueous solution of hydrogen peroxide Set up the burette filled with water as in a standard water displacement experiment 2 mL of 20volume hydrogen peroxide will give enough oxygen almost to fill the burette Weigh out 1 g each of copper II oxide nickel oxide manganese lV oxide and zinc oxide Put 50 mL of water in the flask and add 2 mL of hydrogen peroxide solution Add the 1 g of copper oxide Immediately insert the bung with the delivery tube into the flask Time the volume of oxygen given off at intervals of 15 seconds Plot the volume of oxygen produced every 15 seconds against the time of the reaction Repeat the experiment using the other oxides as catalysts Plot a graph for each experiment Manganese IV oxide is usually used as a catalyst in this reaction The catalyst is not used up during the reaction A catalyst may slow down a reaction as well as speed it up