Kinetics Study on the Reaction between Iodide Ions and Hydrogen Peroxide

The speed of a reaction or the rate of a reaction is defined as the change in concentration of a reactant or product in unit time. It can be expressed as, the rate of decrease in concentration of any one of the reactants or the rate of increase in concentration of anyone of the products. The speed of a reaction or the rate of a reaction is defined as the change in concentration of a reactant or product in unit time. It can be expressed as, the rate of decrease in concentration of any one of the reactants or the rate of increase in concentration of anyone of the products. The reaction between iodide ions and hydrogen peroxide occurs in the acidic medium. In this reaction, hydrogen peroxide oxidises iodide ions to molecular iodine. If calculated amount of sodium thiosulphate is added in the presence of starch solution as an indicator to the above reaction mixture, the liberated iodine reacts with thiosulphate ions as fast as it is formed and is reduced back to iodide ions till all the thiosulphate ions are oxidised to tetrathionate ions. When thiosulphate ions are completely consumed, the liberated iodine reacts with starch solution and gives a blue colour.

This video explains how to study the reaction rate of the reaction of iodide ions with hydrogen peroxide at different concentrations of iodide ions.