Chemistry Lab Report
April 29, 2015
Lab: Reaction Rates
Introduction: In this experiment we studied the reaction of potassium persulfate, K2S2O8, with potassium iodide, KI. All chemical reactions have an energy barrier to overcome before the reaction will proceed. We will record data based on the concentration, temperature and catalyst for each experiment. Once this has been completed it will be graphed.
Procedure: Due to the chemicals being used having hazard gloves are used for the entire procedure. For this lab the materials we used were pipettors and tips, 10 mL graduated cylinders, large test tubes, test tube racks, corks and timers. The larger test tubes allowed for easier mixing of solutions. The first procedure was a concentration study. The concentration allowed for 9 separate trials. A solution table was provided to ensure proper measurements for each of the trials. The pipettors were used to obtain the appropriate amount of each chemical in order to perform the separate trials. Solution A contained; water, 0.3M potassium iodide, 0.4% starch and 0.02M sodium Thiosulfate. Solution B contained 0.1M Potassium Persulfate. Once all of the solutions were measured out. We individually added solution B to solution A, put the cork in the test tube and the timer was started immediately. We then inverted each solution twice. Once inverted we held a white sheet of paper behind each test tube to allow easier viewing of the reaction. Once we noticed a color change the timer was stopped and that time was logged on the data sheet provided. For the second procedure temperature was studied. Using 400 mL beakers we created an ice bath and warm water bath. Solution A and B from trial three of the prior procedure were prepared and placed in each beaker for five minutes. This five minute period allowed the solution to stabilize at the desired temperature. Next we mixed solutions A and B together in the warm and ice baths and started