Wash Bottle Laboratory Exercises: Iodide-Catalyzed H2O2 Decomposition Reaction Kinetics Using the Initial Rate Approach

A wash bottle water displacement scheme is used to determine the kinetics of the iodide-catalyzed H 2 O 2 decomposition reaction. The reagents (total volume 5.00 mL) are added to a test tube that is placed in a wash bottle containing water. The mass of the water displaced in ∼60 s is measured. The reaction is first order in H 2 O 2 and first order in I − . The average rate constant reported by students is 0.0112 ± 0.0002 M −1 s −1 ( N = 17) at ∼20 °C.