Kinetics Lab –The Iodination of Acetone
Overview
How can a rate law expression and a rate constant be determined from the collection of reactant concentration data? What does a rate law tell about a reaction?
Objectives
- How can a rate law expression and a rate constant be determined from the collection of reactant concentration data? What does a rate law tell about a reaction?
- Connect observations to AP Chemistry models and calculations.
Materials Needed
Procedure
Note, all of the solutions have been pre-made (Your Welcome!). Prepare data tables like the ones provided by your teacher. Record all volumes to the nearest 0.01 mL.
Clean four different 10-mL graduated cylinders and four 25-mL graduated cylinders. Assign one for each solution and one for the distilled water. (NOTE: Report what solutions where used in your procedure write-up!)
Using the reaction rate data table provided in this lab (Experiment #1), add the appropriate amounts of each solution to a 125-mL Erlenmeyer flask; however do NOT add the iodine solution yet.
Using a stopwatch, have one person time the reaction as follows: as soon as one lab partner adds the iodine solution to the reaction mixture, start timing the reaction. The reaction will be at an end when no more yellow color is visible in the reaction vessel. The person pouring the iodine solution should continually swirl the Erlenmeyer flask using a magnetic stirrer to keep the reaction thoroughly mixed. The reaction may take up to two minutes. Record the time that is takes to complete the reaction.
Redo each experiment. Record an average time for each experiment.
Repeat procedure steps 2, 3 and 4 for Experiments #2, #3 and #4.
Record the temperature of your last reaction mixture (This will be the temperature for our experiment and our rate constant). Note – The temperature will not be needed for any calculations, only to report the temperature of our rate constant.
Set up a calculations table (as written in this lab) and calculate the reaction concentrations and the rate of disappearance of iodine over time.
Calculate the orders of each reactant and determine the rate law of this experiment.
Calculate the rate constant for this reaction at the temperature you recorded.