 We will do an experiment to determine the exponents in a rate equation. This is called the method of initial rates. We will carry out a reaction between the bromate ion and the iodide ion in an acidic solution. We will vary the iodide ion concentration and keep the concentration of the bromate ion and the hydrogen ion constant. We will then vary the concentration of bromate ion keeping the iodide and hydrogen ion concentration constant. We will then vary the hydrogen ion concentration and keep the bromate and iodide ion concentration constant. This will allow us to determine the exponents in the rate equation. In the 125-milliliter Irmar flask, we will add 10 milliliters of potassium iodide solution, 10 milliliters of a solution of sodium thiosulfate, and 10 milliliters of water. We will swirl the flask to make sure that the solutions are mixed. In the test tube, we will add 10 milliliters of potassium bromate solution, 10 milliliters of a hydrochloric acid solution, and about 1 milliliter of a starch solution. We're going to pour the contents of the test tube into the flask. The bromate ion will oxidize the iodide ion to iodine. The thiosulfate ion, however, will reduce the iodine back to iodide. Once all the thiosulfate is used up, the iodine will react with the starch and turn blue. We will time from when we add the contents of the large test tube to the flask until the solution turns blue. We will do an experiment to determine the energy of activation for the reaction between the bromate ion and the iodine ion in acidic solution. This is the same reaction that we use to determine the exponents in the rate equation. We'll run one of the reaction mixtures at different temperatures and record the time for the blue color to appear.