In this week’s lab experiment, the rate of decomposition of hydrogen peroxide forming oxygen gas will be observed and studied. Since the rate of a chemical reaction is dependent on two things; the concentrations of the reactants and the temperature at which the process is performed, the rate can be measured at which a reactant disappears or at which a product appears. When measuring the rate, the rate law will be applied. The objective of this lab is to demonstrate how the rate changes with varying initial concentrations of hydrogen peroxide by measuring the rate at which oxygen is evolved. Procedure:
To perform this lab, an apparatus must be set up. To assemble the experimental set up, after acquiring the needed materials, the first step is to fill the tub with room temperature water. After that, room temperature water must also be added to the leveling bulb until the buret and the rubber tubing connecting the buret to the leveling bulb are filled. When filling up the leveling bulb, it must be placed near the top of the buret and should not be no more than half full, filled with water. Bubbles must be cleared from the tubing to eliminate possible errors. Once bubbles are cleared, the top of the buret must be connected to a 250 ml Erlenmeyer flask with a rubber tube and stopper and then must be checked for leaks by lowering the leveling bulb. This should now complete the set up for the lab experiment.
Now that the experiment has been set up, to perform this lab, 10 ml of 0.10M KI and 15 ml of distilled water must be added to a 250 ml Erlenmeyer flask. The flask must then be swirled in the water bath to allow the solution to succumb to the same temperature. Once that has been done, 5 ml of 3% of H2O2 must be added to solution in the Erlenmeyer flask and a stopper must then be immediately placed on the flask. For this next step, one person must swirl the flask in the bath at all times...