2. The decomposition of hydrogen peroxide in aqueous solution happens very slowly. A catalyst can be used to speed up this reaction. Objectives: Conduct a catalyzed decomposition of hydrogen peroxide. Calculate the rate constant k for this reaction. Determine the rate law for this reaction. Calculate the activation energy for this reaction. Background

3. Materials Lab quest Netbook Gas pressure sensor Temperature probe 4 test tubes and test tube holder Wash bottle/Distilled water 3 % hydrogen peroxide (0.88M) 100 mL volumetric flask Solid potassium iodide 2 10 mL graduated cylinders plastic pipettes 600 mL beaker Ring stand and clamp Glass pipette and pipette bulb

4. Procedure We will be doing 4 experiments during this lab to determine the rate law of this reaction and the activation energy.

5. Solution Preparation We will be using store bought 3%(0.88M) H 2 O 2 We will need to make 100 mL of a 0.5 M KI solution. How many grams of KI will we need? (molar mass of KI = 166.01 g/mol) 8.3 g In experiment 2 we will be cutting the concentration of our KI in half. In experiment 3 we will be cutting the concentration of our H 2 O 2 in half

6. Data Table ExperimentReactantsTemp ( o C)Rate (kPa/s) 14 mL 0.88 M H 2 O 2 + 1 mL 0.50 M KI 24 mL 0.88 M H 2 O 2 + 1 mL 0.25 KI 34 mL 0.44 M H 2 O 2 + 1 mL of 0.50 M KI 44 mL 0.88 M H 2 O 2 + 1 mL 0.50c M KI

7. Data Analysis Experiment[H 2 O 2 ] After Mixing (M) [KI] After Mixing (M) Rate (M/s) 1 2 3 4

8. Analysis Questions 1. Using your data determine the rate law for this reaction, and calculate the average value of k for the 3 experiments. 2. Determine the average numerical value of k for experiments. 3. The rate law should have been first order in both KI and H 2 O 2 using this information determine the units for k.